WO2021134385A1 - Oxygen-enriched side blowing furnace smelting method for secondary resource having arsenic and dispersed elements by adding ion and chlorinating agent respectively - Google Patents

Abstract

An oxygen-enriched side blowing furnace smelting method for a secondary resource having arsenic and dispersed elements by adding ion and chlorinating agent respectively, comprising: adding a chlorinating agent accounting for 1-1.5% of the total weight of a furnace charge when the furnace charge is proportioned, preparing a material pressing block, and carrying out reduction smelting in an oxygen-enriched side blowing furnace. According to the method, the chlorine content in the raw materials is actively regulated and controlled to be within the range of 1-1.5%, and is 5-15 times of the content of the dispersed elements in the secondary resource. The method is particularly used for chlorinating and volatilizing the dispersed elements to achieve high-power enrichment and recovery of the dispersed elements, and has a remarkable resource utilization effect.

Description

Oxygen-enriched side-blowing furnace smelting method for secondary resources containing arsenic, iron, rarefied elements, and chlorinating agent Technical field

The invention relates to the non-ferrous smelting industry, in particular to an oxygen-enriched side-blowing furnace smelting method in which secondary resources contain arsenic, iron, rarefied elements, and chlorinating agents.

Background technique

In the non-ferrous smelting industry, lead pyrometallurgical smelting fumes generally have typical components: Pb: 30-50%, Bi+Sb+Sn: 1-5%, S: 4-8%, As: 5-25%, SiO2+Fe+CaO: 2～6%, Cd: 2～6%, Se+Te+Tl+In+Ge: 0.02～0.2%; the typical composition of copper pyrometallurgical smelting dust: Pb: 10～25%, Cu: 5～15%, S: 5～8%, As: 5～30%, SiO2+Fe+CaO: 15～25%, Se+Te+Tl+In+Ge: 0.02～0.2%; zinc wet method Typical composition of leaching mud: Pb: 20-40%, Bi+Sb+Sn: 1～5%, S: 8-15%, As: 2-20%, SiO2+Fe+CaO: 20-30%, Se+ Te+Tl+In+Ge: 0.02-0.2%; these non-ferrous metal raw materials are different from primary mine resources and are commonly called secondary resources. They have the following characteristics: First, the main metal Pb, Cu and Bi+Sb+Sn are about 40-60% lower than the primary resources of conventional mines, which is not convenient for smelting and recycling by conventional smelting methods; second, they contain toxic elements Arsenic is much higher than primary resources. It is a toxic solid subject to key environmental protection monitoring and needs to be professionally disposed of with a sound environmental protection process; third, it contains the scattered elements Se, Te, Tl, In, Ge, etc., which are enriched by primary smelting. The proportion of economic value is usually as high as 15-40%, but the content is very low and usually does not reach the lower limit of industrial recycling; fourth, the output of these secondary resources is huge, and the country has an annual increase of up to 2 million tons of new output.

In the past, some people put the lead smelting dust into the reverberatory furnace for reduction smelting, mixed with a large amount of alkali-made thin slag, and produced a large amount of crude lead and a large amount of alkali slag containing arsenic. This kind of alkali slag caused environmental risks and burdens. Some people leached copper fumes with sulfuric acid to achieve separation and extraction of copper and lead and other major metals, but a large amount of arsenic enters the leaching solution. This arsenic-containing wastewater poses risks and burdens to environmental protection. CN102286665A discloses a smelting method for secondary resources containing arsenic. While reducing smelting to recover the main metal lead, arsenic is solidified in the arsenic-iron alloy as a subsequent smelting raw material, and no clear solution is made to the harmlessness of arsenic. Program. CN108085501B discloses a method for classifying sulfur-containing arsenic-containing non-ferrous metal materials with iron to recover the main price metal, and simultaneously fixing sulfur and arsenic in a harmless smelting batching method for the harmless and resourceful disposal of arsenic-containing secondary non-ferrous resources Provides practical and feasible technical solutions. In summary, industrial practice and technological progress have an obvious technical shortcoming, that is, they ignore the simultaneous recovery of the scattered elements Se, Te, Tl, In, Ge, etc., which are accompanied by secondary non-ferrous metal resources. The value of the scattered elements is generally as high as 15-40%, causing a huge waste of precious resources.

Summary of the invention

The purpose of the present invention is to provide a secondary resource containing arsenic, iron, and chlorinating the rare elements on the basis of the dilemma that the secondary resources in the prior art have extremely low content of scattered elements and are difficult to recover. Oxygen-enriched side blowing furnace smelting method, reduction smelting and recovery of the main metal lead in the secondary resource, while chlorinating enrichment of rare elements into the soot smelting method.

The creative idea of the present invention is: on the basis of CN108085501B, inherit the environmental protection smelting process of its classification with iron, sulfur and arsenic, and make the following special design: On the one hand, use the high-temperature carbon reduction and iron smelting in the oxygen-rich side blowing furnace with the rarefied elements. Under the replacement environment, it is easy to be chlorinated by a sufficient amount of chlorinating agent to produce metal chlorides with high vapor pressure and volatilize into the flue gas; on the other hand, a small amount of 1 to 1.5% of chlorinating agents (such as CaCl, KCl, NaCl) Etc.), compared with the main valence metal Pb+Bi+Sb+Sn+Cu in the raw material, the relative amount is less, resulting in weaker chlorination and weaker corrosion to equipment, and relative to the extremely low content For the 0.02-0.2% of the scattered elements, 1 to 1.5% of the chlorinating agent is equivalent to 5 to 15 times the mass ratio, which constitutes a strong chlorination environment to ensure complete volatilization. It is necessary to point out that the chlorine in the raw materials in CN108085501B is regarded as the main harmful substance, which will cause serious adverse effects on the conditions of the smelting furnace, and its content must be strictly controlled to be less than 2.8%, and in the method of the present invention, the chlorine in the raw materials is actively controlled. The chlorine content is in the range of 1 to 1.5%, and it is an ingredient with 5 to 15 times the content of the rare elements. It is especially used for the chlorination and volatilization of the rare elements to achieve high enrichment and recovery, and has a significant resource utilization effect.

To this end, the technical solution adopted by the present invention is: a secondary resource containing arsenic, iron, rarefied elements, and chlorinating agent in an oxygen-enriched side-blowing furnace smelting method, the method steps are as follows:

Step 1. Ingredients: First determine the types of raw materials, chemical composition and demand, and then mix into the furnace charge according to the following ingredients:

A. Select the ferrosilicon calcium slag type suitable for the characteristics of the secondary resources: the weight ratio of SiO2: Fe: CaO in the slag type is (30～35): (18～22): (14～18);

B. Classification of iron distribution:

①0.5-0.6 times the weight of the sum of the total silicon in the charge and the amount of silicon in the coke ash is combined with oxidized iron (for example, "red iron powder" using iron sulfide slag) for calcium ferrosilicon slagging ,

②1.3 to 1.5 times the weight of the total sulfur and total arsenic in the charge of the total sulfur and the total arsenic are reacted to form iron-sulfur matte and arsenic-iron alloy.

C. Main metal content grade: Generally limited by the actual raw material content, usually Pb+Bi+Sb+Sn is selected, and the mixing amount is 18-30% of the total weight of the charge;

D. Selection of the upper limit of the sulfur and arsenic content of the furnace charge: S does not exceed 9%, and As does not exceed 8%;

E. Chlorinating agent: CaCl2 or KCl or NaCl is selected, and the mixing amount is 1 to 1.5% of the total weight of the charge;

F. Moisture content of the charge into the furnace: In order to facilitate the pressing of the ingredients, the moisture content is selected to be 11-14%;

Step 2. Ingredients to make compacted block: that is, the above-mentioned ingredients are mixed and crushed, then pressed into a block, stacked, and air-dried; it is the existing conventional technology, and the details are as follows:

2.1. Shovel the corresponding ingredients from different silos according to the ingredient formula requirements, stack them, and roll them while shoveling, so that the high-moisture muddy material and the powder are infiltrated and mixed. Generally, repeat the shovel and rolling three to four times. It can be mixed evenly;

2.2. Feed the crushed dispersed material into the crusher and break it into bulk material with a lumpiness less than 20mm;

2.3. Put the crushed material into the press to form a block, the block size is selected between 100～150mm;

2.4. Stack the pressed blocks and air-dry them into spare materials with higher strength to reduce the crushing rate during feeding.

Step 3. Enter the oxygen-enriched side-blowing furnace for reduction smelting; it is also carried out according to the existing conventional reduction smelting method, specifically:

3.1. Oxygen-enriched side-blowing furnace type selection: In order to adapt to the characteristics of the compacted block material that is easy to be broken and dusty, the bulge angle of the oxygen-enriched side-blowing furnace should be small, generally 0～2.5 degrees, and the height of the oxygen-enriched side-blowing furnace material column Choose a moderate height of 4～5m;

3.2. Coke ratio selection: The lead sulfate in the charge needs to consume carbon during replacement and reduction. The reaction formula is: PbSO4+Fe+2C=Pb+FeS+2CO2; therefore, it is compared with the coke ratio of the traditional oxygen-enriched side-blowing furnace with agglomerates. 9～11% is generally 2～3% higher than 9～11%, that is, 13～16% of coke-to-material ratio is selected;

3.3. Start-up and operation: The thickness of the bottom coke layer added first when the furnace is opened is the same as the thickness of the tuyere area of the oxygen-enriched side blowing furnace. The bottom lead dosage is about 1.2 to 1.3 times of the actual capacity of the hearth to ensure that the furnace is heated after melting. The lead under the overheated flow of the high-temperature bottom coke layer can heat the hearth to 800℃～1000℃, avoiding the condensation and crusting when the first molten silicon ferro-calcium slag flows into the hearth; adjust the blast volume to normal before the slag hole is not discharged 60 to 80% of the value. Observe the tuyere frequently. When you see the slag rising, immediately use the oxygen tube to open the slag hole to release the slag, and then adjust the blast volume to the normal air coke ratio balance air volume. The air supply pressure is determined by the wind resistance in the furnace and the height of the slag dam. Adapt to adjustment, keep the tuyere bright and enter the normal oxygen-enriched side blowing furnace operation state;

3.4. Smelting reaction in oxygen-enriched side blowing furnace:

3.4.1. The main metal lead in the charge generally exists in the form of lead sulfate, lead sulfide and lead oxide, and the following reactions occur:

PbSO4+Fe+2C=Pb+FeS+2CO2↑

PbS+Fe=Pb+FeS

PbO+CO=Pb+CO2↑

3.4.2. Copper in the charge generally exists in the form of copper oxide, and the following reactions occur:

CuO+CO=Cu+CO2↑

Cu+S=CuS

3.4.3. The iron mixed in the charge and the arsenic in it react as follows:

As2O3+3C=2As+3CO

As+Fe=FeAs

3.4.4. The rarefied elements in the charge generally exist in the form of oxides, and the following chlorination reactions occur:

SeO2+HCl=SeCl4+2H2O

TeO2+HCl=TeCl4+2H2O

TlO2+HCl=TlCl4+2H2O

In2O3+6HCl=2InCl3+3H2O

GeO2+HCl=GeCl4+2H2O.

Step 4. Collect the smelted products;

4.1. Produce crude lead alloys with major price metals, in which Sb, Bi, Sn, Ag, Au, An, etc. in the charge are collected. The direct yield of lead smelting is generally between 80 and 92%, and the yield is about 20 to 25. %;

4.2. Produce calcium ferrosulfur slag, the yield is 30-40%, typical composition: SiO2: 30%, FeO: 25%, CaO: 16%;

4.3. Production of iron sulphur matte, the yield is about 15-25%, typical components: S: 18-20%, Fe: 40-50%, Cu: 2-8%, Pb: 4-7%;

4.4. Produce arsenic-iron alloy with a yield of about 8-16%, typical components: As: 20-25%, Fe: 55-60%, Pb: 0.5-1.5%, arsenic-iron alloy has a large specificity, non-toxic, and can be used Used as a counterweight material instead of steel;

4.5. Produce smoke and dust with a yield rate of 6-8%, typical components: Pb: 20-30%, Cl: 12-18%, As: 5-20%, CaO: 5-9%, Se: 0.2-0.4 %, Te: 0.1 to 0.5%, Tl: 0.08 to 0.2%, In: 0.1 to 0.8%, Ge: 0.01 to 0.04%, Cd: 5 to 15%, K: 4 to 6%.

From the analysis of the smoke and dust composition, it can be seen that due to the addition of the chlorinating agent according to item E in the ingredients, the rare elements in the charge can be volatilized and enriched in the smoke during smelting. Due to the enrichment rate, the content of the rare elements reaches or exceeds the industrial Recycling lower limit grade requirements.

The present invention is based on the prior art recovering the primary metal of secondary resources and harmlessly disposing of arsenic, and according to the characteristics of the extremely low-grade rare elements contained in the raw materials, an appropriate amount of chlorinating agent is creatively blended into the charge. On the one hand, a large excess of chlorinated environment is formed relative to the extremely low content of rare elements; on the other hand, a relatively small amount of weakly chlorinated environment is formed relative to the higher content of the main valence metal, which is smelted in an oxygen-rich side blowing furnace. Efficient and high-rate volatilization of the scattered elements into the smoke and dust for collection, without significant impact on the recovery of the main metal. The method of the present invention avoids the huge waste of precious non-renewable scattered element resources caused by the previous technology, creates extremely high economic value, and reduces the invisibility of the environment caused by the unorganized diffusion of the highly toxic thallium in the scattered elements that cannot be professionally recycled. harm.

Detailed ways

Example 1

Industrial production was carried out according to the method of the present invention in a smelting plant in Hunan. The main raw materials and ingredients used were: ① Lead soot: H2O: 8%, Pb: 45.2%, Bi+Sb+Sn: 3.5%, Ag: 300g/T, Au: 1.0g/T, S: 6.4%, As: 8.7%, SiO2: 1.7%, Fe: 0.5%, CaO: 1.5%, Se+Te+Tl+In+Ge: 0.05%; ②Copper soot: H2O : 4.0%, Pb: 18.3%, Ag: 600g/T, Au: 3.0g/T, S: 8.0%, As: 20%, SiO2: 5.5%, Fe: 1.0%, CaO: 4.6%, Se+Te +Tl+In+Ge: 0.03%; ③ Leaching lead sludge: H2O: 28%, Pb: 28.5%, Ag: 800g/T, Au: 5.0g/T, S: 11.0%, As: 10.8%, SiO2: 3.0%, Fe: 5.0%, CaO: 5.0%, Se+Te+Tl+In+Ge: 0.04%; ④ Iron oxide ingredients (red iron powder): H2O: 15%, Pb: 0.5%, SiO2: 10% , Fe: 45%, CaO: 8%; ⑤ Elemental iron ingredients (magnetic separation iron powder): H2O: 6%, Pb: 3.5%, SiO2: 10%, Fe: 65%, CaO: 5%; ⑥ Chlorination Agent: Cl: 64%, Ca: 35%.

The specific steps implemented are as follows:

Step 1. According to the formula principle of the present invention, the formula weight ratio of the above raw materials is calculated and calculated as: ①:②:③:④:⑤:⑥=25:15:24:14:20:2, according to this formula The composition of the charge is: H2O: 12.74%, Pb: 21.6%, Cu: 1.38%, Bi+Sb+Sn: 1.97%, S: 5.56%, As: 7.76%, Ag: 357g/T, Au: 1.9g/T , Se+Te+Tl+In+Ge: 0.026%, Cl: 1.29%, SiO2: 7.27%, FeO: 20.35%, CaO: 5.28%.

Step 2. Ingredients to make compacted blocks: Use a forklift to mix the ingredients, shovel, and roll repeatedly 3 to 4 times to make the mixture fully uniform; use a crusher to break the piled mixture into bulk materials with a lumpiness of less than 20mm ; Use a press to press the prepared material into a shaped block with a size of 100-150mm; store the shaped block for 2 to 4 days to air dry, and increase the strength of the material block to facilitate handling and less broken.

Step 3. Enter the oxygen-enriched side blowing furnace for smelting: the oxygen-enriched side blowing furnace has a tuyere area width of 1.25m, a furnace length of 4.08m, a hearth area of 5.6m2, and a material column height of 4.5m; select 14.5% of the smelting coke ratio, press the blast Intensity 18m3/㎡·min blows air with a wind pressure of 10Kpa to achieve a stable production capacity of 30～35T/㎡·day. Because the water content of the furnace charge is as high as 10%, the temperature of the furnace top flue gas is maintained at 150～200℃. Normal furnace conditions are smooth.

Step 4. Collect the smelt products:

4.1. The main metal crude lead alloy produced by the smelting of the oxygen-enriched side-blowing furnace captures most of the non-ferrous metals such as gold, silver, bismuth, antimony and tin in the charge. Containing Pb: 95.6%, Ag: 1700g/T, Au: 9.8g/T, Se+Te+Tl+In+Ge<0.001%, the yield is about 20%, and the vertical yield is 85-92%;

4.2. Calcium ferrosilicon slag produced by oxygen-enriched side blowing furnace smelting, its typical composition is SiO2: 30%, FeO: 25%, CaO: 16%, Se+Te+Tl+In+Ge<0.001%; the yield is about It is 35%, usually quenched into loose sand with water.

4.3 The general composition of iron pyrite matte produced by oxygen-enriched side blowing furnace is S: 18%, Fe: 50%, Cu: 5.5%, Pb: 5.0%, As: 1.2%, Se+Te+Tl+In+ Ge<0.001%, the yield is about 26%, layered by specific gravity in a precipitation pot, and collected by cooling.

4.4 The composition of arsenic-iron alloy produced by oxygen-enriched side-blowing furnace is As25%, Fe65%, S0.5%, Pb0.2%, Se+Te+Tl+In+Ge<0.001%, and the yield is about 13%. Iron-cured arsenic is non-toxic and can be used as a counterweight material instead of steel.

4.5 The composition of soot produced by oxygen-enriched side blowing furnace smelting is Pb: 25%, Cl: 16%, S: 8.0%, As: 20%, Se+Te+Tl+In+Ge: 0.417%, and the yield is about 6 %. Analyzing the scattered elements in the charge and smoke, it can be seen that the volatilization rate of the scattered elements from the raw materials to the smoke and dust is greater than 95%, and the enrichment ratio is about 17 times, so that the enrichment from the 100g/ton level of the raw material to several kilograms/ton level Content, so that the further comprehensive recovery of the scattered elements meets and exceeds the lower limit of industrial economic recovery.

Comparative example

As in the other cases of Example 1, only the chlorinating agent is not actively mixed in the ingredients, so that there is no chlorinating agent in the charge, and the products obtained by smelting according to the same method and equipment are as follows:

A. The yield of crude lead alloy is about 20%: Pb 94.5%, Ag1700g/T, Au9.08g/T, Se+Te+Tl+In+Ge: 0.048%. It can be seen that the scattered elements in the charge are about 40%, dispersed Into the crude lead, the enrichment ratio is about 5 times;

B. The yield of calcium ferrosilicon slag is about 35%: In the test, Se+Te+Tl+In+Ge: 0.009%, it can be seen that about 13% of the scattered elements in the charge are dispersed in the slag;

C. The yield of iron pyrite matte is about 26%: In the test, Se+Te+Tl+In+Ge: 0.01%, it can be seen that about 15% of the scattered elements in the charge are dispersed in the iron pyrite matte;

D. Arsenic-iron alloy, the yield is about 13%, the Se+Te+Tl+In+Ge in the test: 0.028%, it can be seen that about 13% of the scattered elements in the charge are dispersed into it.

E. Smoke and dust, the yield is about 6%, the test of Se+Te+Tl+In+Ge: 0.043%, it can be seen that the scattered elements in the charge are dispersed to about 20%, and the relative grade is increased by about 3 times.

Comparing Example 1 and Comparative Example, it is obvious that the smelting method of actively adding chlorinating agent according to the method of the present invention can volatilize more than 95% of the scattered elements in the charge into the smoke and dust, and the enrichment ratio is as high as 17 times. In previous smelting methods that do not actively mix chlorinating agents, about 40% of the scattered elements are dispersed into the crude lead after smelting, about 40% into various slags, and about 20% into the smoke and dust, making it difficult to disperse the precious scattered elements. Recycling and being wasted.

Claims (6)

An oxygen-enriched side-blowing furnace smelting method with secondary resources containing arsenic, iron, rare elements and chlorinating agents, is characterized in that the method includes the following steps: Step 1. Ingredients: First determine the types of raw materials, chemical composition and demand, and then mix into the charge according to the following ingredients: A. Ferrosilicon calcium slag type: The weight ratio of SiO2:Fe:CaO in the slag type is (30～35): (18～22): (14～18); B. Classification of iron distribution: ① 0.5 to 0.6 times the weight of the sum of the total silicon in the charge and the amount of silicon in the coke ash, with iron in the oxidation state, ②1.3 to 1.5 times the weight of the sum of total sulfur and total arsenic in the charge, with elemental iron; C. Main price metal content grade: select Pb+Bi+Sb+Sn, and the mixing amount is 18-30% of the total weight of the charge; D. The upper limit of the sulfur and arsenic content of the furnace charge: S does not exceed 9%, and As does not exceed 8%; E. Chlorinating agent: CaCl2 or KCl or NaCl is selected, and the mixing amount is 1 to 1.5% of the total weight of the charge; F. Moisture content of the charge into the furnace: the moisture content is 11-14%; Step 2. Ingredients to make pressed blocks: mix and crush the above ingredients and press them into blocks, stack them, and air-dry; Step 3. Reducing and smelting into the oxygen-enriched side blowing furnace; Step 4: Collect the smelting product; because the charge is mixed with chlorinating agent, the rare elements in the secondary resources are volatilized and enriched in the smoke and dust of the product during smelting, and the content of the rare elements reaches or exceeds the lower limit of industrial recovery requirements. . The oxygen-enriched side-blowing furnace smelting method for secondary resources containing arsenic, iron, rarefied elements, and chlorinating agent according to claim 1, wherein the crushing in step 2 means that the degree of fragmentation is less than 20mm bulk material. The oxygen-enriched side-blowing furnace smelting method of secondary resources containing arsenic, iron, rare elements, and chlorinating agent according to claim 1, wherein the size of the medium block in step 2 is 100-150 mm. The oxygen-enriched side-blowing furnace smelting method of a secondary resource containing arsenic, iron, rare elements, and chlorinating agent according to claim 1, wherein the oxygen-enriched side-blowing furnace during reduction smelting in step 3 Type requirements: the vent angle is 0 ~ 2.5 degrees, and the height of the material column of the oxygen-enriched side blowing furnace is 4 ~ 5m. The oxygen-enriched side-blowing furnace smelting method of a secondary resource containing arsenic, iron, rarefied elements, and chlorinating agent according to claim 1, wherein the coke ratio during reduction smelting in step 3 is 13- 16%. An oxygen-rich side-blowing furnace smelting method for secondary resources containing arsenic, iron, rarefied elements, and chlorinating agent according to claim 1, wherein the smelted product in step 4 also includes crude lead alloy, silicon Calcium iron slag, iron sulphur matte and arsenic iron alloy.