CN116200598A - Treatment method of tungsten slag by acid method - Google Patents

Abstract

The invention relates to a treatment method of acid-process tungsten slag, which comprises the following steps: s1, dissolving: mixing the tungsten smelting slag with water, and performing heating treatment to obtain a material A; s2, filtering: filtering the material A, separating slag C and tungsten-containing feed liquid, adding water into the slag C, filtering and collecting washing water; s3 ball milling: mixing the washed slag C with an auxiliary material B, and then performing ball milling to obtain a material D; s4, size mixing: mixing the material D with the washing water, and performing size mixing to obtain a material E; s5, leaching: adding phosphoric acid, controlling the concentration of the phosphoric acid in the feed liquid to be more than or equal to 8g/l, then adding sulfuric acid, adjusting the concentration of residual acid in the feed liquid to 15-50g/l, and then heating and leaching to obtain a material F; s6, filtering: and filtering the material F to obtain tungsten-containing enrichment liquid and filter residues. The method adopts a new process to treat the acid-process tungsten smelting slag, so that the consumption of raw materials is reduced, the loss of tungsten carried by the slag is low, and the application prospect is wide.

Description

A method for treating tungsten slag by acid method

technical field

The invention relates to a recovery and treatment technology for tungsten-containing slag, in particular to a treatment method for acid smelting tungsten slag.

Background technique

Scheelite slag refers to the solid waste produced after scheelite is processed by acid process. Usually, the acid method is to leaching scheelite ore through sulfur-phosphorus mixed acid process. Generally, the composition of the sulfur-phosphorus mixed acid is: the phosphoric acid content is 5-10g/l before leaching, and the sulfuric acid content is 5-10g/l before leaching. 300-400g/l.

This kind of slag contains acid and tungsten, the acid content is relatively high, and the tungsten content is about 10%. In order to recover this kind of scheelite slag, the current treatment method for this kind of scheelite is to wash and remove the soluble heteropolyacid first, then dissolve the tungsten in the slag into sodium tungstate, and then precipitate through auxiliary materials to form scheelite; finally return to leaching. As shown in Figure 1: the scheelite slag is first washed by slurrying to remove the acid and soluble tungsten in the slag; then the slurry is filtered and separated, and the separated filtrate is returned to the slurry to enrich the tungsten, and the obtained slag is adjusted again Add auxiliary materials to dissolve the tungsten in the slag, repeat the filtration and separation operation, add calcium chloride to the separated material liquid for tungsten precipitation treatment, and obtain scheelite after filtration.

This treatment method has a long process, many types of auxiliary materials, requires multi-process washing, and consumes a lot of water; the solution and slag formed in the process will take away part of the tungsten, resulting in high tungsten loss.

Contents of the invention

The purpose of the present invention is to overcome the existing problems of recovering tungsten from the scheelite slag obtained by acid smelting scheelite, and to provide a treatment method for acid smelting tungsten slag. The acid smelting tungsten slag contains more impurities Acid, using the characteristic that heteropolyacids are soluble in hot water, the present invention first adds water and heats the tungsten slag of the acid method, and separates the soluble part of the acid and part of the tungsten in the slag from the solid phase to obtain the tungsten-containing material liquid and slag C; Secondly, use the auxiliary material B and slag C to adjust the pH by mixing in the ball mill, and form material D after the initial reaction; finally, by controlling the acidic leaching conditions and leaching under high phosphorus and low acid conditions, the tungsten in material D is dissolved, and the slag is formed under low acid conditions The probability of tungstic acid is low, so it can ensure less tungsten entrainment in the slag, and the tungsten content is lower than 2wt%.

The specific plan is as follows:

A method for treating tungsten smelting slag by acid method, said tungsten smelting slag by acid method is the slag obtained after scheelite is treated with sulfur-phosphorus mixed acid, comprising the following steps:

S1 dissolving: mixing the tungsten smelting slag with water, and performing heat treatment to obtain material A;

S2 Filtration: filter the material A, separate the slag C and the tungsten-containing liquid, wash the slag C with water, and collect the washing water by filtration;

S3 ball milling: ball milling the washed slag C and auxiliary material B to obtain material D;

S4 pulping: mixing the material D and the washing water for pulping to obtain material E;

S5 leaching: add phosphoric acid to the material E, control the phosphoric acid concentration in the feed liquid to be greater than or equal to 8g/l, then add sulfuric acid, adjust the residual acid concentration of the feed liquid to 15-50g/l, and then carry out heating and leaching, the heating temperature 80-100°C, heat preservation for 0.5-3h to obtain material F;

S6 Filtration: Filtrating the material F to obtain tungsten-containing enrichment liquid and filter residue.

Further, the tungsten content in the tungsten smelting slag described in S1 is greater than or equal to 5wt%, the calcium sulfate content is 20-40wt%, and the molybdenum content is 0.06%-0.1wt%; preferably, the tungsten content in the tungsten smelting slag is 9-15wt%.

Further, the heat treatment temperature in S1 is 70-90°C, preferably 75-85°C, and the reaction time is 1-2 hours, so that the slag C obtained by filtering and washing the material A in S2 is neutral .

Further, adding water to S2 for washing, using hot water with a temperature of 40-90°C, preferably hot water with a temperature of 80-90°C.

Further, the auxiliary material B described in S3 is at least one of sodium carbonate, calcium carbonate, lime, and caustic soda, and the mass ratio of the auxiliary material B mixed with the slag C is 1:8-15. The obtained material D has a pH greater than 9.

Further, the auxiliary material B in S3 is sodium carbonate, the mass ratio of sodium carbonate and the slag C mixed is 1:9-12, and the particle size of the material D obtained after ball milling is 0.1-100 microns, In the filter residue obtained after steps S4, S5 and S6, the tungsten content is lower than 1.5wt%.

Further, add phosphoric acid in S5 to control the concentration of phosphoric acid in the feed solution to be 8-15g/l, preferably 8-10g/l;

Optionally, a heteroacid is added to S5, and the acidity of the heteroacid is greater than 60 g/l.

Further, sulfuric acid is added to S5 to adjust the residual acid concentration of the feed liquid to 18-42g/l, and the tungsten content is lower than 2wt%; the residual acid concentration is preferably 20-40g/l, more preferably 20-30g/l .

Further, heat leaching is carried out in S5, the heating temperature is 90-100° C., and the temperature is kept for 0.5-3 hours, so that the tungsten content in the filter residue produced after the material F is filtered in S6 is lower than 1 wt%.

Further, it also includes mixing the tungsten-containing feed liquid described in S3 and the tungsten-containing enrichment liquid described in S6 to recover tungsten, and use the mixed liquid as a mother liquid for processing tungsten ore, so as to achieve tungsten recovery.

Beneficial effect:

In the present invention, the treatment method of tungsten slag by acid method firstly washes the slag, secondly transforms the washed slag mixed auxiliary material B through ball milling, and finally directly returns the ball milling slag for leaching, and filters and discards the slag after it is qualified. The whole process is short, the addition of auxiliary materials is less, the formation of slag and solution is less, and the loss of tungsten is relatively reduced, which has good environmental protection value and economic benefits.

Description of drawings

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings will be briefly introduced below. Apparently, the accompanying drawings in the following description only relate to some embodiments of the present invention, rather than limiting the present invention.

Fig. 1 is the process flow diagram of the treatment process of tungsten smelting slag by acid method in the prior art provided by the present invention;

Fig. 2 is a flow chart of the treatment process of acid tungsten smelting slag provided by an embodiment 2 of the present invention.

Detailed ways

The definitions of some terms used in the present invention are given below, and other unmentioned terms have definitions and meanings known in the art:

Acid method tungsten slag: In the present invention, the acid method tungsten slag is scheelite leached through sulfur-phosphorus mixed acid process, the tungsten content in the tungsten slag is greater than or equal to 5wt%, and has high calcium sulfate, low tungsten, and molybdenum-containing impurities. feature. The residual acid concentration of the tungsten slag produced by the acid method is 10-40g/l.

The main steps of the processing method of acid method smelting tungsten slag of the present invention are as follows:

S1 dissolving: mixing the tungsten smelting slag with water, and performing heat treatment to obtain material A;

S2 Filtration: filter the material A, separate the slag C and the tungsten-containing liquid, wash the slag C with water, and collect the washing water by filtration;

S3 ball milling: ball milling the washed slag C and auxiliary material B to obtain material D;

S4 pulping: mixing the material D and the washing water for pulping to obtain material E;

S5 leaching: add phosphoric acid to the material E, control the phosphoric acid concentration in the feed liquid to be greater than or equal to 8g/l, then add sulfuric acid, adjust the residual acid concentration of the feed liquid to 15-50g/l, and then carry out heating and leaching, the heating temperature 80-100°C, heat preservation for 0.5-3h to obtain material F;

S6 Filtration: Filtrating the material F to obtain tungsten-containing enrichment liquid and filter residue.

Among them, the purpose of S1 dissolution and S2 filtration is to wash away the soluble part of tungsten and wash the slag into neutral, so as to avoid acid ball milling to corrode the mill and waste auxiliary materials.

In the S3 ball mill, the auxiliary material B is used to transform the slag C in the ball mill, and the following reactions mainly occur:

CaWO ₄ +Na ₂ CO ₃ ＝Na ₂ WO ₄ +CaCO ₃

S4 pulping uses the washing water in the whole process, which has low tungsten content and can be used for pulping. At the same time, it can be heated to 80-90°C to prepare for subsequent leaching.

S5 leaching is treated with mixed acid of sulfuric acid and phosphoric acid to recover tungsten in the slag; the key to qualified slag treatment is to reduce the content of residual tungsten in the slag as much as possible, so it is necessary to control the concentration of phosphorus before leaching to be greater than 8g/l, and the use of sulfuric acid can reduce the tungsten in the slag. Equipment corrosion.

Preferred embodiments of the present invention will be described in more detail below. Although preferred embodiments of the present invention are described below, it should be understood that the present invention can be embodied in various forms and should not be limited by the embodiments set forth herein. If no specific technique or condition is indicated in the examples, it shall be carried out according to the technique or condition described in the literature in this field or according to the product specification. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products. In the following examples, if not explicitly stated, "%" refers to percentage by weight.

See Table 1 for the main element contents of the tungsten smelting slags used in the following examples.

Table 1 The main components of acid tungsten smelting slag

Element Ca W Mo Fe Pb Zn Sr Content/wt% 27.29 11.54 0.06 0.07 0.01 0.02 0.01

Embodiment 1 The recovery process of conventional acid method smelting tungsten slag

Referring to Figure 1, take 300g of acid tungsten smelting slag, and process it according to the following process:

Step 1. Mix slurry with 100ml of hot water, heat it to above 80°C, filter and separate to obtain slag A;

Step 2. Slurry A again and add 5ml of phosphoric acid, then adjust the pH to 10 with caustic soda; react at 85°C for 1 hour, then filter and separate; use calcium chloride to precipitate tungsten from the obtained tungsten-containing filtrate to obtain calcium tungstate.

Step 3, calcium tungstate returns to the leaching process.

In the above process, tungsten loss: 2wt% in step 2; 0.8wt% in step 3, so the total tungsten recovery rate is low.

Embodiment 2 New technique of the present invention

Referring to Figure 2, take 300g of acid tungsten smelting slag, and process it according to the following steps:

S1 Dissolving: Mix the tungsten smelting slag with water and heat it to obtain material A. The water used for dissolving can be the filtered washing water during the treatment of the last batch of materials, so as to realize the recycling of water. The purpose of heating is to fully dissolve the heteropolyacid in the slag, and the heating temperature is 90°C for 1 hour.

S2 Filtration: Filter the material A, separate the slag C and the tungsten-containing material liquid, wash the slag C with water, and collect the washing water by filtration. The obtained slag C is washed to make it neutral, which is beneficial to reduce the consumption of the auxiliary material B in the next step.

S3 ball milling: the washed slag C is mixed with auxiliary material B and then ball milled to obtain material D. The auxiliary material B is sodium carbonate, the mass ratio of auxiliary material B and slag C mixed is 1:10, and the particle size of material D after ball milling is 5-6 microns.

S4 pulping: mixing the material D and the washing water for pulping to obtain material E;

S5 leaching: add phosphoric acid to the material E, control the concentration of phosphoric acid in the feed liquid to be equal to 8g/l, then add sulfuric acid, adjust the residual acid concentration of the feed liquid to 38g/l, and then conduct heating and leaching, the heating temperature is 90°C , keep warm for 1h to obtain material F;

S6 Filtration: filter the material F to obtain tungsten-containing enrichment liquid and filter residue, wherein the tungsten content in the filter residue is 1.2wt%, so the recovery rate of tungsten is 98.8wt%.

S7 Tungsten recovery: Mix the tungsten-containing feed liquid described in S3 and the tungsten-containing enrichment liquid described in S6 for tungsten recovery, return the tungsten-containing washing water in the process, and use it as the mother liquid for ore treatment, so as to achieve tungsten recovery.

Compared with Example 1, the tungsten loss is the 2% and 0.8% slag that is taken away by the slag after step 2 and step 3, respectively. This implementation adopts a new process without the 2% of step 2 in Example 1. tungsten loss.

Example 3

Take 300g of acid method tungsten slag and process it according to the following steps:

S1 Dissolving: Mix the tungsten smelting slag with water and heat it to obtain material A. The water used for dissolving can be the filtered washing water during the treatment of the last batch of materials, so as to realize the recycling of water. The purpose of heating is to fully dissolve the heteropolyacid in the slag, and the heating temperature is 90°C for 1 hour.

S2 Filtration: Filter the material A, separate the slag C and the tungsten-containing material liquid, wash the slag C with water, and collect the washing water by filtration. The obtained slag C is washed to make it neutral, which is beneficial to reduce the consumption of the auxiliary material B in the next step.

S3 ball milling: the washed slag C is mixed with auxiliary material B and then ball milled to obtain material D. The auxiliary material B is lime, and the mass ratio of auxiliary material B and slag C mixed is 1:10, and the particle size of material D after ball milling is 5-6 microns.

S4 pulping: mixing the material D and the washing water for pulping to obtain material E;

S5 leaching: add phosphoric acid to the material E, control the concentration of phosphoric acid in the feed liquid to be equal to 8g/l, then add sulfuric acid, adjust the residual acid concentration of the feed liquid to 46g/l, and then perform heating and leaching at a temperature of 90°C , keep warm for 1h to obtain material F;

S6 Filtration: filter the material F to obtain tungsten-containing enrichment liquid and filter residue, wherein the tungsten content in the filter residue is 5.1wt%, so the recovery rate of tungsten is 94.9wt%.

S7 Tungsten recovery: Mix the tungsten-containing feed liquid described in S3 and the tungsten-containing enrichment liquid described in S6 for tungsten recovery, return the tungsten-containing washing water in the process, and use it as the mother liquid for ore treatment, so as to achieve tungsten recovery.

Example 4

Take 300g of acid method tungsten slag and process it according to the following steps:

S1 Dissolving: Mix the tungsten smelting slag with water and heat it to obtain material A. The water used for dissolving can be the filtered washing water during the treatment of the last batch of materials, so as to realize the recycling of water. The purpose of heating is to fully dissolve the heteropolyacid in the slag, and the heating temperature is 90°C for 1 hour.

S2 Filtration: Filter the material A, separate the slag C and the tungsten-containing material liquid, wash the slag C with water, and collect the washing water by filtration. The obtained slag C is washed to make it neutral, which is beneficial to reduce the consumption of the auxiliary material B in the next step.

S3 ball milling: the washed slag C is mixed with auxiliary material B and then ball milled to obtain material D. The auxiliary material B is calcium carbonate, and the amount of the auxiliary material B mixed with the slag C is 1:10, and the particle size of the material D after ball milling is 5-6 microns.

S4 pulping: mixing the material D and the washing water for pulping to obtain material E;

S5 leaching: add phosphoric acid to the material E, control the concentration of phosphoric acid in the feed liquid to be equal to 8g/l, then add sulfuric acid, adjust the residual acid concentration of the feed liquid to 41g/l, and then conduct heating and leaching at a temperature of 90°C , keep warm for 1h to obtain material F;

S6 Filtration: The material F is filtered to obtain tungsten-containing enrichment liquid and filter residue, wherein the tungsten content in the filter residue is 4.9wt%, so the recovery rate of tungsten is 95.1wt%.

S7 Tungsten recovery: Mix the tungsten-containing feed liquid described in S3 and the tungsten-containing enrichment liquid described in S6 for tungsten recovery, return the tungsten-containing washing water in the process, and use it as the mother liquid for ore treatment, so as to achieve tungsten recovery.

Example 5

In this example, the leaching conditions of S5 are studied on the basis of Example 2, material D is taken, and anhydrous salt water is added to make slurry, and material E is obtained. Use the conditions in Table 2 to add different acids for leaching treatment. After adding the acid, the heating temperature is 90 ° C, and the temperature is kept for 1 hour. The material F is obtained and filtered to obtain the tungsten-containing enrichment liquid and filter residue. The tungsten content of the filter residue is detected. The results are shown in Table 2.

Table 2 Tungsten loss under different leaching conditions

serial number first acid Second acid Tungsten content in slag wt% 1 sulfuric acid none 14 2 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l none 12 3 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 5g/l Sulfuric acid, the residual acid concentration of the feed liquid is 40.1g/l 8.8 4 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l Sulfuric acid, the residual acid concentration of the feed liquid is 100g/l 7.9 5 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l Sulfuric acid, the residual acid concentration of the feed liquid is 83.4g/l 8.4 6 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l Sulfuric acid, the residual acid concentration of the feed liquid is 62.7g/l 6.7 7 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l Sulfuric acid, the remaining acid concentration of the feed liquid is 50.8g/l 2.4 8 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l Sulfuric acid, the remaining acid concentration of the feed liquid is 40.2g/l 1.3 9 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l Sulfuric acid, the residual acid concentration of the feed liquid is 31g/l 1.7 10 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l Sulfuric acid, the residual acid concentration of the feed liquid is 20.9g/l 0.95 11 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 8g/l Sulfuric acid, the residual acid concentration of the feed liquid is 1.6g/l 7.5 12 Phosphoric acid, the concentration of phosphoric acid in the feed liquid is 9g/l Sulfuric acid, the residual acid concentration of the feed liquid is 40.1g/l 6.8

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. These simple modifications All belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific implementation manners may be combined in any suitable manner if there is no contradiction. In order to avoid unnecessary repetition, various possible combinations are not further described in the present invention.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (10)

1. A treatment method for tungsten smelting slag by acid method, said tungsten smelting slag by acid method is the slag obtained after scheelite is treated with sulfur-phosphorus mixed acid, it is characterized in that: comprising the following steps: S1 dissolving: mixing the tungsten smelting slag with water, and performing heat treatment to obtain material A; S2 Filtration: filter the material A, separate the slag C and the tungsten-containing liquid, wash the slag C with water, and collect the washing water by filtration; S3 ball milling: ball milling the washed slag C and auxiliary material B to obtain material D; S4 pulping: mixing the material D and the washing water for pulping to obtain material E; S5 leaching: add phosphoric acid to the material E, control the phosphoric acid concentration in the feed liquid to be greater than or equal to 8g/l, then add sulfuric acid, adjust the residual acid concentration of the feed liquid to 15-50g/l, and then carry out heating and leaching, the heating temperature 80-100°C, heat preservation for 0.5-3h to obtain material F; S6 Filtration: Filtrating the material F to obtain tungsten-containing enrichment liquid and filter residue. 2. The method for treating tungsten smelting slag by acid method according to claim 1, characterized in that: the tungsten content in the tungsten smelting slag described in S1 is greater than or equal to 5wt%, the calcium sulfate content is 20-40wt%, and the molybdenum content is 0.06 %-0.1wt%; preferably, the tungsten content in the tungsten smelting slag is 9-15wt%. 3. The method for treating tungsten slag by acid method according to claim 1, characterized in that: the temperature of heat treatment in S1 is 70-90°C, preferably 75-85°C, and the reaction time is 1-2 hours, so that The slag C obtained by filtering and washing the material A through S2 is neutral. 4. The method for treating tungsten slag from acid-based smelting according to claim 1, characterized in that: S2 is washed with water, using hot water at a temperature of 40-90°C, preferably at a temperature of 80-90°C. 5. according to the processing method of the described acid method smelting tungsten slag of claim 1, it is characterized in that: auxiliary material B described in S3 is at least one in sodium carbonate, calcium carbonate, lime, caustic soda, described auxiliary material B and The mass ratio of the slag C mixed is 1:8-15, and the pH of the material D obtained after reaction molding is greater than 9. 6. according to the processing method of acid method tungsten refining slag described in claim 5, it is characterized in that: the auxiliary material B described in S3 is sodium carbonate, and the mass ratio that sodium carbonate mixes with described slag C is 1:9-12, The material D obtained after ball milling has a particle size of 0.1-100 microns, and the tungsten content in the filter residue obtained after steps S4, S5 and S6 is less than 1.5 wt%. 7. The method for treating tungsten slag by acid method according to claim 1, characterized in that: adding phosphoric acid in S5 to control the concentration of phosphoric acid in the feed liquid is 8-15g/l, preferably 8-10g/l; Optionally, a heteroacid is added to S5, and the acidity of the heteroacid is greater than 60 g/l. 8. The method for treating tungsten slag by acid method according to claim 7, characterized in that: add sulfuric acid in S5, adjust the remaining acid concentration of the feed liquid to 18-42g/l, and the tungsten content is lower than 2wt%; The acid concentration is preferably 20-40 g/l, more preferably 20-30 g/l. 9. The method for treating tungsten slag by acid method according to claim 8, characterized in that: heating and leaching is carried out in S5, the heating temperature is 90-100°C, and the heat preservation is 0.5-3h, so that the material F is filtered through S6 In the generated filter residue, the tungsten content is lower than 1wt%. 10. The method for treating tungsten slag by acid process according to any one of claims 1-9, further comprising: mixing the tungsten-containing material liquid described in S3 and the tungsten-containing enrichment liquid described in S6 and then carrying out For tungsten recovery, the mixed liquid is used as the mother liquid for processing tungsten ore, so as to achieve tungsten recovery.

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