TW201334889A - Iron and molybdenum containing pellets - Google Patents

Abstract

Iron and molybdenum containing pellets and a process for producing the pellets are disclosed. A green pellet is produced from mixing an iron containing powder, a molybdenum oxide powder, and a carbonaceous powder. The green pellets can be reduced at a temperature in the range of 400-1500 DEG C. The pellets can be briquetted.

Description

Pellets containing iron and molybdenum

The present invention relates to a method of producing pellets containing iron and molybdenum and pellets produced by the method.

Molybdenum iron is an iron-molybdenum alloy having a molybdenum content of usually 60 to 80% by weight.

In most commercial applications, molybdenum iron is produced from molybdenum trioxide (MoO ₃ ) by carbothermal reduction, aluminothermic reduction or thermal reduction. The carbothermal process produces high carbon molybdenum iron, while the latter two produce low carbon molybdenum iron. Low carbon molybdenum iron is more common than high carbon alloys. The density of the molybdenum iron block produced by such a method is usually about 9 g/cm ³ . These blocks may be difficult to dissolve in the steel melt due to the high melting point of the blocks, for example, the melting point of commercial grade FeMo70 is 1950 ° C, and because the temperature of the steel melt is relatively low, the dissolution of ferromolybdenum is mainly affected by the diffusion process. Effect, which extends the dissolution time of ferromolybdenum. Another factor is the high cost of raw materials in the thermal reduction of aluminum and the reduction of hot. Moreover, in such processes, it is possible to lose about 2% of Mo in the slag.

It is an object of the present invention to provide a novel iron and molybdenum containing material suitable for the addition of molybdenum in the molten industry (e.g., steel, foundry and superalloy industries) and a method of making the material in an equally cost effective manner.

Another object is to provide a novel material containing iron and molybdenum having the same rapid dissolution time in a steel melt.

Another object is to provide a novel low carbon and high molybdenum containing iron and molybdenum material, and a method of making the material in an equally cost effective manner.

At least one of the above objects is achieved, at least to some extent, by a process comprising the steps of producing pellets comprising iron and molybdenum: a) mixing iron-containing powder, molybdenum oxide powder, carbonaceous powder, b) adding liquid, And optionally adding a binder and/or a slag forming agent to the mixture, and granulating to provide a plurality of green pellets; c) drying the green pellets as appropriate to reduce the moisture content to less than 10% by weight.

The moisture content is defined as water present in the raw pellets in addition to the crystal water. The moisture content can be determined by loss on drying (LOD) analysis according to ASTM D2216-10. By drying the green pellets to a moisture content of less than 10% by weight, the risk of cracking due to rapid vaporization of the liquid is minimized when heated at elevated temperatures. The raw pellets are preferably dried to a moisture content of less than 5% by weight, more preferably less than 3% by weight.

The preferred method includes at least one of the following steps: d) heat treating the green pellets at a temperature in the range of from 400 to 800 ° C, and preferably for at least 20 minutes, more preferably for at least 30 minutes.

e) reducing the pellet derived from step c) or step d) at a temperature in the range of 800-1500 ° C, preferably 800-1350 ° C, more preferably 1000-1200 ° C, preferably for at least 10 minutes, more preferably at least 20 minutes, the best is at least 30 minutes.

Preferably step f), cooling the pellet from step d) or step e) to a temperature below 200 ° C in a non-oxidizing atmosphere (for example reducing or inert) to avoid re-oxidation of the pellet, more preferably in an inert atmosphere Below 150 °C.

The pellets produced may be further subjected to additional method steps comprising: g) crushing and/or grinding the pellets; h) screening the crushed and/or ground pellets; i) hot pressing at a temperature in the range of 250-1000 ° C, preferably 400-800 ° C, and more preferably between two counter-rotating rolls; j) agglomerating the pellet into 2 - 300 pellets Pellet agglomerates.

The dry matter composition of the raw pellet containing iron and molybdenum produced by the proposed method is preferably as follows: 1-25% by weight of Fe, 15-40% by weight of O, 5-25% by weight of C, and less than 15% by weight of other elements. And the remaining at least 30% by weight of Mo. More preferably, the dry matter composition of the raw pellets containing iron and molybdenum is: 1-25% by weight of Fe, 15-30% by weight of O, 5-25% by weight of C, less than 15% by weight of other elements, and at least the rest 40% by weight Mo.

The dry matter composition refers to the composition of the dried sample, that is, any moisture present in the raw pellets is excluded.

When the melt is alloyed in industrial production, non-reducing green pellets can be used as a substitute for conventionally manufactured ferromolybdenum alloys or even as a substitute for molybdenum oxide. Raw pellets containing iron and/or molybdenum can be produced at a lower cost than standard grade ferromolybdenum.

From method step d) and/or step e), it is possible to produce pellets containing iron and molybdenum having a geometric density in the range of 1.0 to 6.0 g/cm ³ , preferably in the range of 2.0 to 5.0 g/cm ³ , and a group thereof It is: 2-30% by weight of Fe, less than 30% by weight of O, less than 20% by weight of C, less than 15% by weight of other elements than Mo, Fe, C and O, and at least 40% by weight of Mo. When alloyed with molybdenum in a melt operation, the pellets can replace the conventionally manufactured ferromolybdenum alloy. Pellets containing iron and/or molybdenum can be produced at a lower cost than standard grade ferromolybdenum. As shown in the examples below, pellets containing iron and molybdenum dissolve faster than standard grade molybdenum iron. The oxygen content in the pellets may be partially or completely reduced depending on the reduction time, the relative amount of carbon relative to the amount of reducible oxides, and the reduction temperature.

The invention will now be described in more detail with respect to the drawings and with reference to the drawings.

Figure 1 reveals that the dissolution time of the materials of the present invention is much shorter than the dissolution time of the reference level.

Figure 2 shows a schematic overview of a process for making pellets containing iron and molybdenum according to the present invention.

In the mixing table 3 , a powder mixture is prepared by mixing an iron-containing powder, a carbonaceous powder, and a molybdenum oxide powder.

Typically, iron powder is added in an amount of from 1 to 10% by weight, but up to 25% by weight of Fe can be added. Iron powder is primarily used to reinforce the pellets (e.g., acting as a binder), but can be varied to balance the amount of Fe and Mo required in the final product. The molybdenum oxide powder is typically added in an amount of from 70 to 90% by weight.

Preferably, the amount of carbonaceous powder is selected such that it is capable of reducing the oxygen content to 0-10% by weight while maintaining a carbon content of less than 5% by weight after complete reduction. Preferably, the carbonaceous powder is balanced so that most, preferably all, molybdenum oxide can be reduced to Mo, such as MoOx, where x 0.5. Therefore, most of the residual oxide after reduction is an oxide which is difficult to reduce with carbon. Examples of oxides which are difficult to reduce with carbon are Al ₂ O ₃ , SiO ₂ , MgO, CaO. The raw pellets produced from the powder mixture can be reduced in the reduction furnace 6 as described below. Alternatively, non-reducing raw pellets can be used as alloying additives in the manufacture of iron and steel.

In the mixing table 3 , the powder may be mixed under dry conditions, that is, no liquid is added during the mixing, but it is preferably mixed by adding a liquid, preferably water, under humid conditions. It is preferred to add 5-15% by weight of water during mixing. The dust removal problem is minimized by adding water during mixing.

The molybdenum oxide powder may be milled in the rod mill 1 before being added to the mixing table 3 . Of course, other mills, grinders or crushers can be used to split the molybdenum oxide into smaller particles. In addition, the iron-containing powder and/or the carbonaceous powder may be split into smaller particles by grinding and/or milling and/or crushing.

The ground and/or milled and/or crushed molybdenum oxide particles may be sieved in sieve 2 to provide the desired particle distribution. Of course, the sieving can also be applied to iron-containing powders and/or carbonaceous powders.

In one embodiment, the molybdenum oxide powder and the carbonaceous powder are mixed and ground together, and then the iron-containing powder is added and mixed with the molybdenum oxide powder and the carbonaceous powder. However, any combination of mixing sequences can be performed.

The mixing in the mixing station 3 can be performed batchwise or continuously.

Adhesives and/or slag formers may optionally be added during mixing. The binder, as the case may be, may be an organic or inorganic binder. The binders may be, for example, carbon-containing binders that partially replace the carbonaceous powder. Other binders may be, for example, bentonite and/or dextrin and/or sodium citrate and/or lime. The slag forming agent, as the case may be, may be limestone, dolomite and/or olivine. The total amount of binder and/or slag form, as the case may be, may be from 1 to 10% by weight, more preferably less than 5% by weight, based on the dry weight of the mixture. Binders are optionally present because the iron-containing powder provides a sufficiently strong pellet (e.g., at least 200 Newtons/pellet after drying).

The prepared powder mixture is transferred from the mixing station 3 to the granulator 4 . In the granulator 4 , the powder mixture is granulated to obtain a plurality of raw pellets. If the powder is dry-mixed in the mixing table 3 , the liquid is supplied at the time of granulation. If the powder is wet-mixed in the mixing table 3 , an additional liquid is optionally supplied at the time of granulation. The granulator 4 is preferably a disc granulator or a drum granulator.

During mixing and granulation, the amount of liquid added amounts to about 5% to 25% by weight of the mixture, more preferably 10 to 20% by weight, for example, 10% by weight during mixing and 5% by weight during granulation.

The pellets produced by the granulator 4 are referred to herein as raw pellets. Immediately after the granulator 4 , the green pellets typically have a compressive strength of about 10-20 Newtons per pellet. The shape of the raw pellets is typically spherical, spherical or ellipsoidal.

To reduce the moisture content, the green pellets are transferred to a dryer 5 , such as a rotary dryer. Of course many other types of industrial dryers can be used. The water vapor is preferably removed by gas flow or by vacuum. The pellets are dried until the desired moisture content is reached. Preferably, the green pellets are dried to a moisture content of less than 10% by weight, more preferably less than 5% by weight, most preferably less than 3% by weight. The green pellets are preferably dried at a temperature in the range of 50 to 250 ° C, more preferably 80 to 200 ° C, and most preferably 100 to 150 ° C. In order to improve the economics of the method, the drying time is preferably from 10 to 120 minutes, more preferably from 20 to 60 minutes. But longer drying times are certainly possible. In addition, the raw pellets can also be dried without active heating, for example at ambient air temperature. After drying, the raw pellets had a maximum moisture content of 10% by weight. Hereinafter referred to as dry raw pellets.

Reducing the moisture content has several advantages. One advantage is to minimize the risk of cracking in the reduction furnace 6 . The raw pellets may be broken due to rapid vaporization of residual liquid in the pellets when heated at a high temperature. In addition, after drying, the dried raw pellets are surprisingly strong and therefore do not require compaction before, during or after reduction. In Example 1 below, the dried green pellets had a compressive strength of about 450-500 Newtons per pellet. Iron-containing powders act as binders when mixed under wet conditions and therefore do not require additional binders. Carbonaceous powder also contributes to the strength of the pellets. Therefore, the addition of the binder during mixing is a step as the case may be (the term binder excludes iron-containing powder and carbonaceous powder). The compressive strength of the dried green pellets may range from 200 to 1000 Newtons per pellet, with a preferred compressive strength of 300 to 800 Newtons per pellet. This compressive strength is sufficient to effectively treat the pellets, including reduction in a rotary kiln. More robust pellets can be produced by the addition of binders such that the compressive strength is greater than 1000 Newtons per pellet (if desired).

After the dryer 5 , the dried green body can be used as an alloying additive in the manufacture of iron and steel. The strength and shape of the raw pellets make it easy to transport and handle, and the shredding loss is low. It has been surprisingly found that the use of dry green pellets as alloying additives does not produce any discernable molybdenum loss.

The dried raw pellets may be partially or completely reduced in a reduction furnace such as a rotary kiln 6 . In the rotary kiln 6 , the raw pellets are heat treated at a furnace temperature in the range of 400 to 1500 °C.

In step d), at a temperature in the range of from 400 to 800 ° C, preferably below 700 ° C, the dried green pellets are heat treated as appropriate for at least 20 minutes. Preferably, the heat treatment step d), as the case may be, is not more than 2 hours, preferably less than 1 hour. The molybdenum trioxide can be reduced to molybdenum dioxide by a heat treatment step at a low temperature. This step can be used as a pre-reduction step prior to reduction step e) or as a primary reduction step in the manufacture of partially reduced pellets. The heat treatment step as the case may be carried out in the same furnace as in the reduction step e) See below). Alternatively, it is possible to transfer the partially reduced pellets to another furnace for the reduction step e).

In step e), preferably from 800 to 1500 ° C, preferably from 800 to 1350 ° C, more preferably from 1000 to 1200 ° C, the pellet derived from step c) or step d) is reduced, preferably lasting At least 10 minutes, and can be at least 20 minutes, or even at least 30 minutes. By monitoring the formation of CO/CO ₂ , it is possible to determine when the reduction process is completed. Preferably, the reduction time in step e) is at most 10 hours, preferably at most 2 hours, more preferably at most 1 hour. Depending on the reduction time, the reduction temperature and the relationship between the carbon in the pellet and the reducible oxide, the reducible oxide of the pellet may be partially or completely reduced.

It has been unexpectedly discovered that green pellets can be dried at elevated temperatures without reduction of MoO ₃ discernible sublimation losses. Thus, the claimed process produces a simplified process with improved yield and higher Mo content in the final product. That is, the pre-reduction step d) need not be performed before step e), so that when the temperature is raised to the range of 800-1500 ° C, the range of 400-800 ° C can be quickly passed.

During the reduction, the carbon source can react with the reducible oxides in the pellet to form CO and CO ₂ . In addition, residual moisture can be vaporized. The reduction time can be optimized by measuring the formation of CO and CO ₂ ; in detail, since CO _{2 is} mainly formed during the first few minutes of reduction after CO formation, CO is the main until the carbon source is consumed or has Restore all reducible oxides.

The reduction reaction is endothermic and requires heat. It is preferred to generate heat by heating without affecting the atmosphere in the furnace, and it is more preferable to generate heat by electric heating.

The type of furnace suitable for the heat treatment step and the reduction step as the case may be, for example, a rotary kiln, a rotary hearth furnaces, a shaft furnace (shaft) Furnaces, grate kilns, travelling grate kilns, tunnel furnaces or batch furnaces. Other types of furnaces for solid state direct reduction of metal oxides can also be used.

In a preferred embodiment, a rotary kiln is used to reduce the pellets. In a rotary kiln, the raw pellets from step c) are fed into a rotary kiln that rotates about a slightly inclined horizontal axis and are transferred from the inlet of the kiln towards the exit of the kiln as the kiln rotates about its axis.

The atmosphere in the furnace 6 is preferably supplied by supplying an inert gas or a reducing gas at one end of the furnace, preferably a weak reducing gas such as H ₂ /N ₂ (volume ratio of 5:95) and pumping air at the opposite end (for example, reaction) gases (e.g., CO, CO ₂ and H ₂ O) and the supply of gas), more preferably 8 countercurrent furnace outlet 6 of the supply side in an inert gas or reducing gas, and at the inlet side 7 of the furnace 6 to control the gas evacuated. That is, it is preferred to supply an inert gas or a reducing gas in a countercurrent flow.

Preferably, operating at a pressure in the range of from 0.1 to 5 standard atmospheres, preferably from 0.8 to 2 standard atmospheres, more preferably from 1.0 to 1.5 standard atmospheres, and most preferably from 1.05 to 1.2 standard atmospheres. furnace.

In a possible specific example, the first portion of the kiln provides a temperature zone (preheating zone) in the range of 400-800 ° C, wherein 50-100 wt% of MoO _{3 in} the raw pellets is reduced to MoO ₂ by the carbonaceous powder, and The second portion downstream of the first portion provides a temperature zone in the range of 800-1500 ° C, wherein 50-100 wt% of residual molybdenum oxide is reduced to Mo by residual carbonaceous powder.

In an alternative embodiment, to reduce the amount of external heat required, oxygen or air may be supplied to the preheating zone to react with the formed carbon monoxide to form a carbon dioxide gas. If air is used, the nitrogen absorption of the pellets can be increased. With oxygen, the absorption of nitrogen during the heating and reduction steps can be minimized.

At the outlet 8 of the reduction furnace, the pellets are transferred to the cooling section 9 , providing step f): cooling the pellets from step d) or step e) below in a non-oxidizing atmosphere (for example reducing or inert) The temperature of 200 ° C, to avoid re-oxidation of the pellets, more preferably less than 150 ° C in an inert atmosphere. The atmosphere may be, for example, 95 vol% N ₂ and 5 vol% H ₂ atmosphere. If the nitrogen content of the pellets is required to be extremely low, the pellets can be cooled in a nitrogen-free atmosphere, such as an argon atmosphere.

The pellets produced may be further subjected to additional method steps comprising: g) crushing and/or grinding the pellets; h) screening the crushed and/or ground pellets; i) at 250-1000 ° C, Preferably, the temperature is in the range of 400-800 ° C, and more preferably between two counter-rotating rolls; j) the pellets are coalesced into pellet agglomerates comprising from 2 to 300 pellets.

Molybdenum oxide powder

The molybdenum oxide powder is preferably a molybdenum trioxide powder. The powder may also be a mixture of molybdenum dioxide powder or molybdenum trioxide powder and molybdenum dioxide powder.

The molybdenum powder should include 50-80% Mo, and the remaining elements are oxygen and impurities. The purer the molybdenum oxide grade, the purer the pellets containing iron and molybdenum. On the other hand, however, the purer grade of MoO _{3 is} more expensive.

In a preferred embodiment, industrial grade MoO _{3 is used} . These powders are not as expensive as the purer grades of MoO ₃ and may contain oxides that are difficult to reduce in solid state reduction with carbon. Examples of such oxides are, for example, Al ₂ O ₃ , SiO ₂ and MgO. Fortunately, these oxides can be easily transferred into the slag phase when alloyed in a steel melt, and thus can be allowed to be in the product.

Preferably, at least 90% by weight of the molybdenum oxide powder particles pass through a test sieve having a nominal pore size of 300 μm, and at least 50% by weight of the molybdenum oxide powder particles pass through a test sieve having a nominal pore size of 125 μm. More preferably, at least 90% by weight of the molybdenum oxide powder particles pass through a test sieve having a nominal pore size of 125 μm, and at least 50% by weight of the molybdenum oxide powder particles pass through a test sieve having a nominal pore size of 45 μm. The nominal pore size in this application is in accordance with ISO 565:1990 and is hereby incorporated by reference.

In one embodiment, at least 90% by weight, more preferably at least 99% by weight, of the molybdenum oxide powder particles pass through a test sieve having a nominal pore size of 250 μm, more preferably 125 μm, and most preferably 45 μm.

Iron-containing powder

The iron-containing powder is preferably an iron powder containing at least 80 wt% Fe, preferably at least 90 wt% Fe, more preferably at least 95 wt% Fe, most preferably at least 99 wt% Fe. The iron powder may be iron sponge powder and/or water atomized iron powder and/or aerosolized iron powder and/or iron dust and/or iron sludge powder. For example, the dust filter X-RFS40 from Höganäs AB, Sweden is a suitable powder.

The iron powder may be partially or completely replaced by the iron oxide powder, such as, but not limited to, a powder consisting of one or more of the following groups: FeO, Fe ₂ O ₃ , Fe ₃ O ₄ , FeO(OH) (Fe ₂ O ₃ *H ₂ O). The iron oxide powder may be, for example, rust. Preferably, the iron-containing powder contains at least 50% by weight of metallic iron, more preferably at least 80% by weight of metallic Fe, and most preferably at least 90% by weight of metallic Fe.

Preferably, at least 90% by weight of the iron-containing powder particles pass through a test sieve having a nominal pore size of 125 μm, and at least 50% by weight of the iron-containing powder particles Pass a test sieve with a nominal pore size of 45 μm.

In one embodiment, at least 90% by weight, more preferably at least 99% by weight of the iron-containing powder particles pass through a test sieve having a nominal pore size of 125 μm, more preferably 45 μm. In one embodiment, at least 90% by weight, more preferably at least 99% by weight of the iron-containing powder particles pass through a test sieve having a nominal pore size of 20 μm.

Carbonaceous powder

The carbonaceous powder is preferably selected from the group consisting of sub-bituminous coal, bituminous coal, lignite, smokeless media, coking coal, petroleum coke, and bio-carbon (such as charcoal), or carbonaceous powder processed from such resources. The carbonaceous powder may be, for example, soot, carbon black, activated carbon. The carbonaceous powder may also be a mixture of different carbonaceous powders.

Regarding the selection of the carbonaceous powder, the reactivity of carbon is preferably considered because the productivity and yield of molybdenum depend on this factor. High reactivity is required. In particular, a carbonaceous powder that reacts at a low temperature (preferably <700 ° C) is required. For example, German lignite (brown coal) typically reacts at a lower temperature than petroleum coke and is therefore suitable due to the equally high reactivity at lower temperatures. Charcoal, bituminous coal and sub-bituminous coal can also exhibit the same high reactivity. Particularly suitable examples are soot, carbon black and activated carbon.

The amount of carbonaceous powder is preferably determined by analyzing the amount of oxides in the molybdenum oxide powder and, optionally, the iron-containing powder. Preferably, the amount of reducible oxide is determined. The oxygen content can be analyzed, for example, by LECO® TC400. Furthermore, it is preferred to also consider the maximum allowable carbon content in the pellet. Preferably, the stoichiometric amount or a slight excess amount of the reducible metal oxide in the molybdenum oxide powder and the iron-containing powder is selected. However, the amount of carbon can also be lower than the stoichiometric amount.

The amount of carbonaceous powder can be optimized by measuring the carbon and oxygen content of the pellets produced (e.g., by making pellets in a laboratory electric furnace and measuring carbon and oxygen levels). Based on the measured values, the amount of carbonaceous powder can be optimized to achieve the desired carbon and oxygen content in the pellets produced. Some oxides that may be present in the molybdenum oxide powder are difficult to reduce with carbon. All oxides that have a higher affinity for oxygen at the highest temperature of reduction will remain in the finished product as oxides and thus will not consume carbon during the reduction process. The oxides may, for example, be oxides of Si, Ca, Al and Mg, and may be present, for example, if coarser levels of molybdenum trioxide, such as industrial molybdenum trioxide, are used. However, in many applications of steel metallurgy, it can be treated, for example, by moving these oxides into the slag of the steel melt and may thus allow it to be in the pellet. If a lower amount of such oxides and elements is desired, a purer grade of molybdenum trioxide can be used, such as a grade containing less or no such oxide.

By controlling the amount of carbonaceous powder and matching it to the amount of reducible oxide in the green pellets, the carbon content (after reduction) can be prepared to be less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.1% by weight. %, and preferably less than 0.05 wt% or even 0.01 wt% of pellets containing iron and molybdenum. These pellets can be used, for example, when alloying low carbon steel.

However, it is also possible to produce fully reduced pellets having a carbon content in the range of from 1 to 10% by weight.

Preferably, at least 90% by weight, more preferably at least 99% by weight, of the carbonaceous powder particles pass through a test sieve having a nominal pore size of 125 μm, and at least 50% by weight of the carbonaceous powder particles pass a nominal pore size of 45 μm. Test screen.

In one embodiment, at least 90% by weight, more preferably at least 99% by weight of the carbonaceous powder particles pass through a test sieve having a nominal pore size of 45 μm, and at least 50% by weight of the carbonaceous powder particles pass the nominal pore size 20 μm test sieve. In one embodiment, at least 90% by weight, more preferably at least 99% by weight, of the carbonaceous powder particles pass through a test sieve having a nominal pore size of 20 μm.

Raw pellets containing iron and molybdenum

The dry matter composition of the raw pellet containing iron and molybdenum is as follows: 1-25% by weight Fe, 15-40% by weight O, 5-25% by weight C, less than 15% by weight except for O, C, Mo and Fe Other elements, and the remainder at least 30% by weight Mo.

The iron is preferably in the range of from 1.5 to 20% by weight, more preferably from 2 to 15% by weight, even more preferably from 2 to 10% by weight.

The carbon is preferably from 7 to 20% by weight.

The oxygen is preferably from 15 to 30% by weight.

Molybdenum is preferably from 40 to 65% by weight.

Other elements are preferably at least 1% by weight and less than 10% by weight, more preferably at least 2% by weight and less than 7% by weight.

In the subsequent reduction step, as the reduction proceeds, the relative amounts of iron and molybdenum in the pellet will increase. Of course, the same is true for other residual elements.

The dried green pellets may have a compressive strength in the range of from 200 to 1000 Newtons per pellet, preferably from 300 to 800 Newtons per pellet.

In operation, when the molten alloy, Mo is added to the melt in consideration of price and / or yield, green pellets can be cost effective alternative to standard FeMo powder or composition of MoO _3. Typically, this can be added to, for example, an electric arc furnace (EAF) and this addition, for example Mo, is added to stainless steel, tool steel or high speed steel.

The average diameter of the raw pellets is preferably in the range of from 3 to 35 mm, preferably from 5 to 25 mm. Excessive pellets may extend the required reduction time, while too small pellets may be difficult to handle.

The geometric density of the green pellets starts at 1.0 g/cm ³ , preferably at least 1.2 g/cm ³ . The density can also be limited to at least 1.5 g/cm ³ or at least 2.0 g/cm ³ . The geometric density is preferably less than 4.0 g/cm ³ . The geometric density may also be limited to less than 3.5 g/cm ³ , or less than 3.2 g/cm ³ or less than 3.0 g/cm ³ or less than 2.9 g/cm ³ or less than 2.8 g/cm ³ . The lower geometric density results in a higher porosity, which results in a shorter dissolution time of the pellets. The geometric (encapsulated) density can be measured according to ASTM 962-08.

The shape of the raw pellets is typically spherical, spherical or ellipsoidal. When processed, this form reduces the risk of shredding compared to the compressed briquetted form. In addition, the flow properties are superior to the compact.

Reducing pellets containing iron and molybdenum

Pellets containing iron and molybdenum may be produced by the proposed process step d) and/or step e), the composition of which is: 2-30% by weight Fe, less than 30% by weight O, less than 20% by weight C, less than 15% by weight of other elements than O, C, Mo and Fe, and the balance of at least 40% by weight of Mo, preferably at least 50% by weight of Mo.

The molybdenum trioxide in the pellet may be partially reduced to, for example, a pellet containing MoO _x wherein 0.5 < x < 3, preferably 1 x 2.6. When the pellets are made, the amount of carbonaceous powder required is less than the amount required to reduce all of the reducible oxides. Thus, the pellets can be prepared by selecting a relative amount of carbonaceous powder below the stoichiometric amount.

However, partially reduced pellets can be prepared to have residual carbon in the pellet which can then be activated to reduce residual reducible oxides, such as when pellets are added to the steel melt. The pellets can be prepared by controlling the reduction temperature and duration, for example by heat treatment at 400-800 ° C to partially reduce the pellets.

The partially reduced pellets are preferably reduced to contain less than 30% by weight of O, more preferably less than 25% by weight of O, typically from about 10 to 20% by weight, and the residual carbon content is preferably less than 15% by weight, more preferably It is 5-15% by weight. The partially reduced pellet preferably has a molybdenum content of at least 40% by weight, more preferably at least 50% by weight, most preferably at least 60% by weight.

For many applications, however, it is preferred that the O content is less than 10% by weight, more preferably less than 8% by weight, even more preferably less than 6% by weight, most preferably less than 4% by weight, and preferably, only a small amount of oxygen is derived from molybdenum oxide. Not reduced, ie the pellet contains MoO _x , where x 0.5. Preferably, substantially all of the molybdenum oxide is reduced to Mo, i.e., wherein x is about zero. Herein, the residual oxygen content mainly comes from the hardly reduced molybdenum oxide powder and the oxide in the iron-containing powder, such as oxides of Si, Ca, Al and Mg. Pellets having an oxygen content of less than 2% by weight, if desired, can be prepared using relatively pure grades of molybdenum oxide powder, iron-containing powder, and carbonaceous powder. However, since many of these hard-to-restore oxides can be treated in steel melt metallurgy (e.g., moved into the slag phase), they can be allowed to be in pellets containing iron and molybdenum. The lower limit of oxygen can be about 0% by weight, but typically the oxygen is at least 1% by weight, more typically at least 2% by weight.

The molybdenum content in the pellets can be controlled by varying the relative proportion of the molybdenum oxide powder relative to the iron-containing powder. For substantially completely reduced pellets (ie pellets containing MoOx, where x 0.5), the molybdenum content is preferably controlled in the range of 60 to 95% by weight. The Mo content is more preferably in the range of 65 to 95% by weight, and the optimum Mo content is in the range of 70 to 95% by weight. Surprisingly, it has been found that reduced pellets having a molybdenum content of from 80 to 95% by weight have an extremely high dissolution rate. This result is due to the very high specific surface area and regardless of the extremely high melting point of these alloys (2100-2500 ° C).

By balancing the carbon addition, it is possible to control the reduction pellets to have a carbon content of less than 5 wt.%, less than 2 wt.%, less than 0.5 wt.%, less than 0.1 wt.%, or less than 0.05 wt.%. Low carbon pellets can be used, for example, when alloying low carbon steel. However, in some applications, such as in the production of high carbon steel or cast iron, it may be desirable to have a carbon content in the range of 1-5% by weight.

The iron content of the pellets is preferably in the range of 2 to 25% by weight, more preferably 3 to 20% by weight. The iron content can also be limited to 4-15% by weight or 5-10% by weight. The iron content of the pellets can be controlled by varying the relative proportion of iron-containing powder relative to the molybdenum oxide powder.

When alloyed in a melt operation, the reduced pellets can be a cost effective alternative to MoO ₃ powder or standard FeMo, considering the price and/or yield of Mo added to the melt. Typically, this can be added to, for example, an electric arc furnace (EAF) and the addition, for example Mo, is added to stainless steel, tool steel or high speed steel.

Depending on the purity of the powder mixture, the pellets may contain other elements. It is difficult to reduce oxides. Other elements than Mo, Fe, C, and O may be allowed to be less than 15% by weight. The total amount of other elements than O, C, Mo and Fe is preferably less than 10% by weight, more preferably less than 7% by weight. The amount of other elements is primarily controlled by the purity of the molybdenum trioxide, but may also be derived from iron-containing powders, impurities in the carbonaceous powder, and from the reaction with elements in the surrounding atmosphere during heating, reduction or cooling. The high purity grade of molybdenum trioxide, iron-containing powder and carbonaceous powder are used, and the total amount of elements other than O, C, Mo and Fe can be kept less than 1% by weight if necessary. Elements from the group of Si, Ca, Al, and Mg, if present in the pellet, are primarily bonded in the form of an oxide. For example, in a steel melt, the ruthenium in the form of a ruthenium oxide may be easier to handle than the ruthenium dissolved in the alloy crystal lattice. In some embodiments, other elements may be limited to at least 1% by weight or at least 2% by weight.

Preferably, in some embodiments, other elements are limited to: a maximum of 2% by weight N, more preferably a maximum of 1% by weight N; a maximum of 1% by weight S, more preferably a maximum of 0.5% by weight S; a maximum of 2% by weight Al, more Preferably, 1.5% by weight of Al; a maximum of 2% by weight of Mg, more preferably 1% by weight of Mg; a maximum of 2% by weight of Na, more preferably a maximum of 1% by weight of Na; a maximum of 4% by weight of Ca, more preferably of 2% by weight of Ca; 6 wt% Si, more preferably up to 3 wt% Si; up to 1 wt% K, more preferably up to 0.5 wt% K; up to 1 wt% Cu, more preferably up to 0.5 wt% Cu; up to 1 wt% Pb, more preferably maximum 0.1% by weight of Pb; up to 1% by weight W, more preferably up to 0.1% by weight W; Up to 1% by weight V, more preferably up to 0.1% by weight V; and the remaining elements are preferably each up to 0.5% by weight, more preferably at most 0.1% by weight each, and most preferably at a maximum of 0.05% by weight.

In some embodiments, the Si content is in the range of 0.5 to 3% by weight, the Ca content is in the range of 0.3 to 2% by weight, the Al content is in the range of 0.1 to 1% by weight, and/or the Mg content is in the range of 0.1 to 1% by weight. Within the scope.

Preferably, in the pellet, an element of the group of Si, Ca, Al and Mg, if present in combination as an oxide, is at least 50% by weight, preferably at least 90% by weight.

The nitrogen content is mainly determined by the nitrogen content in the atmosphere during heating, reduction and cooling of the pellets. By controlling the atmosphere in these steps, the nitrogen content can be less than 0.5 wt%, preferably less than 0.1 wt%, and most preferably less than 0.05 wt%.

The average diameter of the pellets is preferably in the range of 3 to 30 mm, preferably 5 to 20 mm. Excessive pellets may extend the required reduction time, while too small pellets may be difficult to handle.

The geometric density of the pellets starts at 1.0 g/cm ³ , preferably at least 1.2 g/cm ³ . The density can also be limited to at least 1.5 g/cm ³ or at least 2.0 g/cm ³ . The geometric density is preferably less than 4.0 g/cm ³ . The geometric density may also be limited to less than 3.5 g/cm ³ , or less than 3.2 g/cm ³ or less than 3.0 g/cm ³ or less than 2.9 g/cm ³ or less than 2.8 g/cm ³ . The lower density results in a higher porosity, and the salty messenger makes the dissolution time of the pellets shorter. Density is measured according to ASTM 962-08.

The apparent density of the pellets (as determined by pycnometry) is preferably in the range of 5-10 g/cm ³ . The apparent density can also be limited to the range of 6-8 g/cm ³ .

The bulk density of the pellets (as determined by filling a can having a volume of 1 liter with a pellet and weighing) is preferably in the range of 0.5 to 3 g/cm ³ , more preferably 1.0 to 2.0 g/cm ³ .

The open porosity (measured at 4.45 psia by mercury intrusion pores) is preferably in the range of 0.1 to 0.6 cm ³ /g. The open porosity can also be limited to the range of 0.2-0.45 cm ³ /g.

The intermediate opening pore diameter (as measured by mercury intrusion pores at 4.45 psia) is preferably in the range of 0.5-20 μm. The diameter of the intermediate opening pores can also be limited to the range of 2-10 μm, or in the range of 3-6 μm.

Preferably, from 20 to 95%, more preferably at least 50%, optimally at least 70% of the pore volume (as measured by a mercury intrusion pore meter at 4.45 psia) is from a pore in the range of from 1 to 10 μm.

The open porosity (as measured by a mercury intrusion pore meter at 4.45 psia) is preferably in the range of 50-80 vol%.

The BET surface area is preferably in the range of from 0.1 to 10 m ² /g. The BET value can also be limited to 0.4-4 m ² /g or 0.6-2 m ² /g or 0.8-1.5 m ² /g.

The compressive strength of the pellets is preferably in the range of from 200 to 1000 Newtons per pellet. The compressive strength can also be limited to the range of 300-800 Newtons/pellets.

The pellet shape is typically spherical, spherical or ellipsoidal. When processed, this form reduces the risk of shredding compared to the compressed compact form, which typically has sharp edges. In addition, the flow properties are superior to the compact. In addition, it can be manufactured at a lower cost because the briquetting step is not required.

In some applications, it may be desirable to have other shapes than spheres, spheres, or ellipsoids. For example, depending on how the conveyor belt is configured As such, the pellets transported on the conveyor belt may roll on the belt.

Pellet agglomerates containing 2-300 pellets are less likely to roll off the conveyor belt. The pellets can be coalesced by means of a binder such as glue. Preferably, the agglomerates contain from 2 to 20 pellets, more preferably from 5 to 15 pellets.

It is also possible to form pellet agglomerates by filling the plastic bag with pellets and preferably thermally shrinking the plastic around the pellets and/or vacuum contracting. Preferably, the agglomerates comprise from 30 to 300 pellets, more preferably from 50 to 200 pellets, most preferably from 75 to 150 pellets.

Another way to avoid the problem is to fill the container, such as a metal can, with pellets. The internal volume of the container is preferably in the range of 100-125000 cm ³ .

Of course, the pellets can also be agglomerated or placed in a container in the manner described above.

The pellets may further be at a temperature in the range of from 250 to 1000 ° C, preferably from 400 to 800 ° C, and more preferably between two counter-rotating rolls, preferably in the range of from 60 to 200 kN per cm of the active roller width. Hot pressing under the pressing force. Suitable hot presses are commercially available, for example, from Maschinenfabrik Köppern GmbH & Co. The binder may be added as appropriate during the hot pressing step. The compact volume is preferably between 15 and 200 cm ³ . Of course, the raw pellets can also be hot pressed. The geometric density of the compact is in the range of 3.0 to 8.0 g/cm ³ , preferably 4.0 to 6.0 g/cm ³ .

Powder containing iron and molybdenum

The pellets may also be crushed into irregularly shaped fragments, such as coarse powders containing iron and molybdenum, wherein the nominal pore size according to ISO 3310-1:2000 is at least 250 μm, preferably at least 500 μm, more preferably at least The 1 mm test sieve contained 90% by weight of powder particles.

The pellets can be further milled and optionally sieved to provide a fine powder containing iron and molybdenum. Preferably, the fine powder particle size, wherein at least 90% by weight, more preferably at least 99% by weight of the particles pass the test according to ISO 3310-1:2000, the nominal pore size is 250 μm, more preferably 125 μm, and most preferably 45 μm screen. For example, fine powder can be provided as a core for filling a cored wire for injection molding or fusion bonding applications. The wires are typically comprised of a metal sheet and a core filler comprising a metal powder. In the injection alloying, the metal piece can be surrounded by winding, for example, paper. The wire diameter, the thickness of the metal sheet, the type of metal used for the metal sheet, and the particle size of the powder are suitable for a particular application.

The powder containing iron and molybdenum for the cored wire preferably has the following composition: 2-25% by weight of Fe, less than 25% by weight of O, less than 10% by weight of C, less than 15% by weight of other elements and at least 60% by weight of Mo . The powder containing iron and molybdenum used for the cored wire preferably has the following composition: 3 to 20% by weight of Fe, preferably 4 to 15% by weight of Fe, more preferably 5 to 10% by weight of Fe; less than 10% by weight of O, preferably Less than 8 wt% O, more preferably less than 6 wt% O, most preferably less than 4 wt% O; less than 5 wt% C, preferably less than 2 wt% C, more preferably less than 0.5 wt% C, most preferably less than 0.05 wt% C; less than 10% by weight of other elements, preferably less than 7% by weight of other elements and Fe, most preferably less than 1% by weight of other elements, and the balance of at least 65% by weight of Mo.

Example 1

By 3% by weight of fine granular iron powder (<40 μm, >99 wt% Fe, X-RSF40 from Höganäs AB) mixed with 84% by weight of technical grade molybdenum oxide (Mo>57 wt.%, <40 μm) and 13% by weight of carbon powder (<20 μm, Carbon Black) A mixture was prepared. Water was added to the mixture and raw pellets were made in a disc granulator. The moisture content of the pellets was about 10% by weight as measured using LOD according to ASTM D2216-10. Thereafter, the pellet was dried at room temperature to a moisture content of 2 wt%.

The green pellets were reduced in a batch furnace at a temperature of 1100 ° C in a 95 vol% N ₂ and 5 vol % H ₂ atmosphere for a period of 2 hours. Thereafter, the pellet was cooled to a temperature of about 100 ° C, and then the atmosphere was evacuated and removed from the furnace. The result was a pellet weight of about 0.4 grams and a diameter of about 6-7 mm. The average geometric density of the pellets was determined to be 2.6 g/cm ³ as measured according to ASTM 962-08.

The pellets were ground to a powder and the chemical composition of the powder was determined. The results are presented in Table 1.

The oxygen content of the pellets is mainly derived from oxides that are difficult to reduce, such as oxides of Mg, Al, Si, and Ca. These oxides may be present in technical grade molybdenum trioxide and are difficult to reduce. Therefore, by using a purer grade of molybdenum trioxide, the oxygen content can be significantly reduced. However, in many applications, such oxides may be allowed in the pellet because it is rapidly separated into slag.

Example 2

Figure 1 shows the dissolution rate of a standard reference grade solid ferromolybdenum compared to the inventive iron and molybdenum containing pellets (i.e., the novel ferromolybdenum grade). Pellets of the same batch as in Example 1 were provided and thus the pellets had the composition as in Table 1. The average geometric density of the pellets was determined to be 2.6 g/cm ³ as described in Example 1.

The reference material is 10 standard ferromolybdenum containing 70% by weight of molybdenum, no more than 2% impurities and the balance being iron. Each block has a size of about 10 x 50 mm.

The objective of the experiment was to evaluate whether pellets containing iron and molybdenum have a faster dissolution time than standard ferromolybdenum.

The first and second steel melts were prepared and analyzed for composition. The target composition of the melt was 5.0 wt.% Mo, 0.6 wt.% C, the balance of Fe and the Mo content in the two steel melts was initially 0 wt%. Both steel melts were maintained at a temperature of about 1550 ° C during the experiment. Mo was added to the first melt in the form of pellets containing iron and molybdenum (consistent with the pellets described in Example 1 herein), and a reference grade block was added to the second steel melt. The pellets and reference grades were separately added to their respective steel melts in one batch. Test samples were taken from each steel melt every 30 seconds to measure the Mo content therein. Ten test samples were taken per melt, and Figure 1 shows how the Mo content of each melt changes over time. It can be seen that the steel melt alloyed with pellets increases faster than the Mo content in the steel melt alloyed with reference grades of standard ferromolybdenum.

Example 3

By using 2.5% by weight of fine granular iron powder (<40 μm, >99 wt% Fe, X-RSF40 from Höganäs AB) and 84% by weight of industrial grade molybdenum oxide Mixture A was prepared by mixing (Mo > 57 wt.%, < 40 μm) and 13.5% by weight of carbon powder (<20 μm, Carbon Black). Water was added to the mixture and raw pellets were made in a disc granulator. After granulation, the green pellets were dried at a temperature of 90 ° C for 2 hours to reduce the moisture by at least 2 wt%.

The raw pellets were reduced in a rotary furnace at a temperature of 1120 ° C for a period of 0.5 hours. The weak reducing gas 95 vol% N ₂ and 5 vol% H ₂ atmosphere were supplied countercurrently during the reduction. Thereafter, the pellet was cooled to a temperature of about 100 ° C under a protective atmosphere. The result was a pellet weight of about 1.9 grams and a diameter of about 12 mm.

Two pellets were tested in a mercury intrusion pore meter under pressure of 4.45 psia (instrument: Micromeritics AutoPore III 9410). Analysis 330 μm Ø Aperture range of 0.003 μm. The results are presented in Table 2. It can be seen that the total open pore volume is measured to be 0.32 cm ³ /g and the intermediate open pore diameter is 4 μm. The open porosity was determined to be 68 vol% and the pore area was 0.7 m ² /g. These data show that the pellets have a fine porous structure that increases the rate of dissolution in the steel melt. The geometric (encapsulated) density was determined to be 2.1 g/cm ³ . The skeleton (visual) density was determined to be 6.56 g/cm ³ using a mercury intrusion pore meter. The skeleton (visual) density was also determined to be 7.36 g/cm ³ by means of a helium pycnometer (instrument: AccuPyc 1330, Micromeritics).

The BET surface area was determined to be 0.98 m ² /g (instrument: Gemini 2360, Micromeritics).

In Figure 3, a plot of log differential intrusion and pore diameter is plotted. As can be seen, most of the pores have a pore diameter between 1-10 μm and a narrow band around the median pore diameter of 4 μm. In Figure 4, a plot of cumulative insrusion and pore diameter is plotted. As is apparent from the figure, more than 70% of the pore volume is from pores in the range of 1-10 μm.

The bulk density of the pellets was determined by filling a 1 liter volume of the cans with pellets and weighing them to a value of 1.5 g/cm ³ .

The size and shape of the pellets results in an equally large macroscopic surface area of the plurality of pellets, i.e., the outer surface of the pellet. In addition, the pellets have an equally large open porosity and pore structure that provides an equally large internal microscopic surface area. The combination of a large microscopic surface area and a large macroscopic surface area contributes to a higher dissolution rate and minimizes Mo sublimation losses when Mo is added to the steel melt, for example as an alloying additive.

Example 4

The compressive strength of the green pellet of the mixture A of Example 3 was examined and compared with the compressive strength of the green pellet prepared from the mixture B. Mixture B was prepared by mixing 84% by weight of technical grade molybdenum oxide (Mo > 57 wt.%, < 40 μm) with 13.5% by weight of carbon powder (< 20 μm, carbon black). That is, the essential difference between mixture A and mixture B is that mixture B does not contain There is iron powder. The mixed powder is wetted and after mixing, the wet mixture is transferred to a disc granulator where raw pellets are produced. The compressive strength was determined by increasing the load on the pellets until crushing. After removing from the granulator for 1 hour, the raw pellet of the mixture A had a compressive strength of 50 Newtons/pellet, and the raw pellet of the mixture B had a compressive strength of 37 Newtons/pellet.

In a ventilated dryer, after drying at 90 ° C for 2 hours, the average compressive strength of the dried green pellets of the mixture A was determined to be 530 Newtons per pellet, and the average compressive pressure of the dried raw pellets of the mixture B was determined. The strength was determined to be 155 Newtons/pellets. This shows that the addition of iron significantly increases the compressive strength of the dried green pellets.

Figure 1 shows the dissolution rate of the pellets of iron and molybdenum according to the invention compared to the solid ferromolybdenum of the reference grade.

Figure 2 is a schematic overview of a process for making pellets containing iron and molybdenum in accordance with the present invention.

Figure 3 is a graph showing the logarithm of the intrusion amount and the pore diameter of pellets containing iron and molybdenum according to the present invention.

Figure 4 is a graph showing the cumulative intrusion amount and pore diameter of pellets containing iron and molybdenum according to the present invention.

Claims (28)

A method of producing pellets comprising iron and molybdenum comprising the steps of: a) mixing iron-containing powder, molybdenum oxide powder and carbonaceous powder; b) adding a liquid, preferably water, and optionally adding a binder and/or Or slag forming agent into the mixture and granulating to provide a plurality of green pellets; and c) drying the green pellets as appropriate to reduce the moisture content to less than 10% by weight. The method of claim 1, comprising at least one of the steps of: d) heat treating the green pellets at a temperature in the range of from 400 to 800 ° C, and preferably for at least 20 minutes; and e) at 800- The pellets derived from step c) or step d) are reduced at a temperature in the range of from 1500 ° C, preferably from 800 to 1350 ° C, more preferably from 1000 to 1200 ° C, preferably for at least 10 minutes, more preferably at least 20 minutes. , best for at least 30 minutes. The method of claim 2, wherein the heat treatment step d) and/or the reduction step e) is carried out in a furnace supplied with an inert gas or a reducing gas, preferably a weak reducing gas. The method of claim 3, wherein the heat treatment step d) and/or the reduction step e) is carried out at an operating pressure of from 0.1 to 5 standard atmospheres, preferably from 0.8 to 2 standard atmospheres. The method of claim 4, wherein the heat treatment step d) and/or the reduction step e) is carried out at an operating pressure in the range of 1.05-1.2 standard atmospheric pressure. The method of claim 5, wherein the inert gas or reducing gas system is supplied in countercurrent. The method of any one of clauses 1 to 6, which comprises drying the green pellets to a moisture content of less than 5% by weight, preferably less than 3% by weight. The method of any one of the preceding claims, wherein the raw pellets are dried at a temperature in the range of from 50 to 250 ° C, preferably from 80 to 200 ° C, more preferably from 100 to 150 ° C. The method of any one of claims 2 to 8, wherein the method comprises one or more of the following steps: f) cooling the pellets to a temperature below 200 ° C in a non-oxidizing atmosphere, Preferably less than 150 ° C, preferably in an inert atmosphere; g) crushing and / or grinding the pellets; h) screening the crushed and / or ground pellets; i) at 250- 1000 ° C, preferably in the range of 400-800 ° C, and more preferably between two counter-rotating rolls; and j) agglomerated pellets into pellets containing 2-300 pellets Things. The method of any one of clauses 1 to 9, wherein the molybdenum oxide powder contains 50 to 80% by weight of Mo. The method of any one of clauses 1 to 10, wherein at least 90% by weight of the molybdenum oxide powder particles pass through a test sieve having a nominal pore size of 300 μm, and at least 50% by weight of such The molybdenum oxide powder particles passed through a test sieve having a nominal pore size of 125 μm. The method of claim 1, wherein the method of any one of claims 1 to 11 is Wherein the iron-containing powder contains at least 80% by weight of Fe, preferably at least 90% by weight, more preferably at least 95% by weight, most preferably at least 99% by weight. The method of any one of clauses 1 to 12, wherein at least 90% by weight of the iron-containing powder particles pass through a test sieve having a nominal pore size of 125 μm, and at least 50% by weight of the The iron powder particles passed through a test sieve having a nominal pore size of 45 μm. The method of any one of clauses 1 to 13, wherein at least 90% by weight of the carbonaceous powder particles pass through a test sieve having a nominal pore size of 125 μm, and at least 50% by weight of such The carbonaceous powder particles passed through a test sieve having a nominal pore size of 45 μm. The method of any one of clauses 1 to 14, wherein the carbonaceous powder is selected from the group consisting of sub-bituminous coal, bituminous coal, smokeless medium, lignite, coking coal, petroleum coke, and biochar, especially charcoal. The method of any one of clauses 1 to 15, wherein the carbonaceous powder is selected from the group consisting of soot, carbon black and activated carbon. A raw pellet containing iron and molybdenum having a geometric density of less than 4.0 g/cm ³ and a dry matter composition as follows: 1-25% by weight of Fe, preferably 1.5-20% by weight; 15-40% by weight O, preferably 15 -30% by weight; 5-25% by weight C, preferably 7-20% by weight; less than 15% by weight of other elements, preferably less than 10% by weight of other elements, and at least 30% by weight of Mo, preferably at least 40 weight%. The raw pellet of claim 13 which satisfies at least one of the following conditions: a moisture content of less than 10% by weight, preferably less than 5% by weight; and a compressive strength of from 200 to 1000 Newtons per pellet, preferably 300-800 Newtons/pellet range; geometric density of at least 1.2 g/cm ³ , preferably at least 1.5 g/cm ³ ; geometric density less than 3.5 g/cm ³ , preferably less than 3.2 g/cm ³ ; In the range of 3-35 mm, preferably in the range of 5-25 mm. A reduced iron and molybdenum containing pellet having a geometric density of less than 4.0 g/cm ³ and having a weight percent composition as follows: 2-30% by weight Fe; less than 30% by weight O; less than 20% by weight C; less than 15 weight Other elements of %; and the remainder at least 40% by weight of Mo, preferably at least 50% by weight of Mo. The reduced pellets of claim 19, wherein the pellets contain 2-25% by weight of Fe, preferably 3-20% by weight of Fe, more preferably 4-15% by weight of Fe, most preferably 5-10 Weight % Fe. The reduced pellets of any one of clauses 19 to 20, wherein the pellets comprise: less than 10% by weight of other elements, preferably less than 7% by weight of other elements. The reduced pellets of any one of clauses 19 to 21, wherein the pellets comprise: at least 1% by weight of other elements, preferably at least 2% by weight of other elements Prime. The reduced pellets of any one of clauses 19 to 22, wherein the pellets comprise: at least 60% by weight Mo, preferably at least 65% by weight Mo, more preferably at least 70% by weight Mo . The reduced pellets of any one of clauses 19 to 23, wherein the pellets comprise: less than 10% by weight O, preferably less than 8% by weight O, more preferably less than 6% by weight O , preferably less than 4% by weight O. The reduced pellets of any one of clauses 19 to 24, wherein the pellets comprise: less than 5% by weight C, more preferably less than 0.5% by weight C. The reduced pellets of any one of clauses 19 to 25, wherein the pellets comprise: 80-95% by weight of Mo. The reduced pellets of any one of clauses 19 to 23, wherein the pellets comprise: 10-20% by weight O, and 5-15% by weight C. The reduced pellet according to any one of claims 19 to 27, which satisfies at least one of the following conditions: compressive strength in the range of 200-1000 Newtons/pellets, preferably 300-800 Newtons Within the range of pellets; geometric density of at least 1.2 g/cm ³ , preferably at least 1.5 g/cm ³ ; geometric density less than 3.5 g/cm ³ , preferably less than 3.2 g/cm ³ ; diameter in the range of 3-30 mm Preferably, it is in the range of 5-20 mm.