CN115927860A

CN115927860A - Process method for recovering tin, iron and manganese by eluting tantalum slag with sulfuric acid

Info

Publication number: CN115927860A
Application number: CN202211722968.6A
Authority: CN
Inventors: 石宏娇; 石仁章; 石仁才; 石俊阳; 汪琴; 石宏森
Original assignee: Leiyang Yanxin Non Ferrous Metals Co ltd
Current assignee: Leiyang Yanxin Non Ferrous Metals Co ltd
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2023-04-07

Abstract

A process method for recovering tin, iron and manganese from tantalum slag by sulfuric acid elution is characterized in that water is added into tantalum slag to leach soluble sulfuric acid, ferrous sulfate and manganese sulfate in the tantalum slag, and acid filtrate and tin-containing filter residues are separated through filter pressing; fe in the acidic filtrate ²⁺ Oxidation to Fe ³⁺ And make Fe ³⁺ Separating the precipitate, press-filtering to obtain iron residue, adding sodium carbonate into the filtrate to obtain manganese carbonate precipitate, and press-filtering to obtain manganese residue. The method separates the residual sulfuric acid, ferrous sulfate and manganese sulfate in the tantalum slag by leachingThe method can reduce the improper influence on the slag form during the recovery of the pyrogenic fuming furnace and the adverse influence on the environment caused by a large amount of sulfur acid-containing flue gas; meanwhile, the grade of tin is improved, and the additionally recovered iron and manganese also have certain resources and economic benefits. The method realizes real environment-friendly recycling and harmless utilization of valuable resources which cannot be directly utilized by the fuming furnace.

Description

Process method for recovering tin, iron and manganese by eluting tantalum slag with sulfuric acid

Technical Field

The invention belongs to the field of waste recovery and environmental protection, and particularly relates to a process method for eluting sulfuric acid from tantalum slag containing tin, iron and manganese and comprehensively recovering the tin, iron and manganese.

Background

Tantalum is an important rare high-melting metal and has been widely used in many fields. The method for smelting tantalum ore by adopting concentrated sulfuric acid to cure and roast at high temperature is to change tantalum into soluble tantalum, then extract the soluble tantalum by using water, and then recover the tantalum ore from filtrate, wherein if the tantalum ore contains tin, iron and manganese, the rest tantalum slag contains 15-20% of sulfuric acid, 7-8% of Sn, 6-15% of Fe, 6-10% of Mn, and the balance of water and gangue. Tin contained in the tantalum slag belongs to a high-value resource, and can be generally treated by a fuming furnace to recover high-grade tin-containing smoke dust, but because the raw materials contain a large amount of sulfuric acid, the environment-friendly load of smelting smoke is huge, the operation is difficult, and the fuming furnace equipment is damaged sometimes; on the other hand, the fuming furnace slag is not suitable for smelting due to the high manganese content, so that the difficulty is caused, a large amount of filter slag is overstocked, the resource is difficult to utilize and is wasted, and meanwhile, the serious potential safety hazard of environmental protection is formed.

Disclosure of Invention

The invention aims to provide a process method for recovering tin, iron and manganese by sulfuric acid elution of tantalum slag, aiming at overcoming the defects of the prior art, so as to elute the tantalum slag containing tin, iron and manganese by sulfuric acid and recover the tin, iron and manganese.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a process method for recovering tin, iron and manganese from tantalum slag eluted sulfuric acid comprises the following steps, and is combined with the steps shown in figure 1:

A. and (5) washing once. According to the solid-liquid ratio (weight) of 1: (1.2-1.6), adding water into the tantalum slag, pulping, stirring and leaching soluble sulfuric acid, ferrous sulfate and manganese sulfate in the tantalum slag, performing filter pressing, and separating acid filtrate and tin-containing filter residue; and C, feeding tin-containing filter residues into the step B, and obtaining acidic filtrate for later use.

The tantalum slag contains 15-20% of sulfuric acid, 7-8% of Sn, 6-15% of Fe, 6-10% of Mn and the balance of water and gangue. Wherein Fe exists in a ferrous sulfate form, and Mn exists in a manganese sulfate form.

B. And (5) secondary water washing. According to the solid-liquid ratio (weight) of 1: (1.2-1.6), adding water into the tin-containing filter residue, pulping, stirring, and performing filter pressing to obtain a filter residue, namely a tin-containing tantalum slag product, wherein the product contains 13-18% of Sn and is less than or equal to 0.6% of Mn, the tin grade in the tin-containing tantalum slag is improved, the manganese content is reduced, a fuming furnace is facilitated to produce high-tin smoke dust, and the subsequent pyrometallurgical process is facilitated; and returning the filtrate to the step A for recycling.

C. Adding hydrogen peroxide into the acidic filtrate obtained in the step A to oxidize Fe in the filtrate ²⁺ Is Fe ³⁺ The addition amount of the hydrogen peroxide depends on Fe in the tantalum slag ²⁺ Depending on the amount of Fe ²⁺ Total oxidation to Fe ³⁺ Then adding sodium hydroxide to adjust pH to 3.6-3.8 to obtain Fe ³⁺ Precipitating, separating, and press-filtering to obtain filter residue, namely iron slag with Fe content of 45-55%, and filtrate for later use.

D. And D, adding sodium carbonate into the filtrate obtained in the step C until the final pH value of the solution is 10-10.5, and simultaneously reacting the sodium carbonate with manganese sulfate in the filtrate to generate manganese carbonate precipitate, wherein the reaction formula is as follows: na (Na) ₂ CO ₃ +MnSO ₄ →MnCO ₃ ↓+Na ₂ SO ₄ And performing filter pressing to obtain filter residue, namely manganese residue, wherein the Mn content is 25-35%, and the filtrate is reserved.

E. D, sending the filtrate obtained in the step D into an MVR evaporator for evaporation, supersaturating to separate out sodium sulfate crystals, and centrifugally separating and drying the crystals to obtain a sodium sulfate product; c, returning the condensed water obtained by evaporation to the step B for recycling; and returning the mother liquor obtained by centrifugation to the MVR evaporator for recycling.

After the tantalum slag containing tin, iron and manganese is treated by the method, residual sulfuric acid, ferrous sulfate and manganese sulfate in the tantalum slag can be leached and separated, so that the improper influence on slag types during recovery of a pyrogenic process fuming furnace and the adverse influence of a large amount of sulfuric acid-containing flue gas on the environment are reduced; meanwhile, the grade of tin is improved, the improvement range reaches 200 percent, the recovery index of tin is greatly improved, and the economic benefit is increased; the iron and manganese which are recovered additionally have certain resources and economic benefits. The method realizes real environment-friendly resource utilization and harmless utilization of valuable resources which cannot be directly utilized by the fuming furnace.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The content of each substance herein is a mass content.

Example 1

Under laboratory conditions, 330g of tin-iron-manganese-tantalum slag (containing 7% of Sn, 12% of Fe, 6.5% of Mn and 16% of sulfuric acid) is added into 500mL of water, stirred and leached at normal temperature for about 30 minutes, and filtered by a vacuum filter to obtain a primary filter cake and a filtrate (primary washing water). Adding water with the weight of 1.5 times into the primary filter cake, pulping, stirring uniformly, carrying out secondary washing and leaching, then carrying out vacuum filtration to obtain a secondary filter cake and filtrate, drying the secondary filter cake, and testing to obtain the high-tin iron-removing manganese-tantalum slag which contains about 18 percent of Sn, about 0.8 percent of Mn and about 1.0 percent of Fe and is washed for the second time, thereby being beneficial to volatilizing and recycling tin in the slag by a fuming furnace. And returning the filtered water after the secondary washing to the former liquid for recycling. And (3) washing the obtained primary washing water by adopting secondary countercurrent water to obtain a solution containing sulfuric acid, ferric sulfate and manganese sulfate with high content, adding about 45mL of hydrogen peroxide with the mass concentration of 24%, stirring for about 15 minutes to convert ferrous iron in the solution into ferric iron, adding NaOH solution with the mass concentration of about 30%, regulating the pH value of the solution to 3.6-3.8, carrying out vacuum filtration on the slurry to obtain a filter cake containing ferric iron and a filtered clear solution containing manganese sulfate, and drying the iron-containing filter cake to assay about 45% of Fe. Adding an appropriate amount of Na into the above manganese sulfate-containing clear solution ₂ CO ₃ The following chemical reaction takes place in the solution: mnSO ₄ +Na ₂ CO ₃ ＝MnCO ₃ ↓+Na ₂ SO ₄ Vacuum filtering the slurry to obtain MnCO when the pH of the solution is controlled at 10.5 ₃ Filter cake and Na-containing ₂ SO ₄ Clear solution, dried filter cake and test, and the Mn content is 36 percent, which is a good raw material of manganese.

The NaSO-containing product obtained above is treated ₄ Evaporating and concentrating the solution in a beaker on an electric furnace after the solution is accumulated to generate supersaturated Na ₂ SO ₄ Crystallizing to make the process meet the requirement of environmental protection treatment. The NaSO thus obtained ₄ The product can be added with value.

Claims

1. A process method for recovering tin, iron and manganese by sulfuric acid elution of tantalum slag is characterized by comprising the following steps:

A. adding water into the tantalum slag, pulping, stirring and leaching soluble sulfuric acid, ferrous sulfate and manganese sulfate in the tantalum slag, performing filter pressing, and separating acid filtrate and tin-containing filter residue; b, feeding tin-containing filter residues into the step B, and obtaining acidic filtrate for later use; wherein, the tantalum slag contains 15 to 20 percent of sulfuric acid, 7 to 8 percent of Sn, 6 to 15 percent of Fe and 6 to 10 percent of Mn, the Fe exists in a ferrous sulfate form, and the Mn exists in a manganese sulfate form;

B. adding water into the tin-containing filter residue, pulping, uniformly stirring, and performing filter pressing to obtain a filter residue, namely a tin-containing tantalum residue product;

C. b, adding hydrogen peroxide into the acidic filtrate obtained in the step A until Fe in the filtrate ²⁺ Oxidation to Fe ³⁺ Then adding sodium hydroxide to adjust the pH value to 3.6-3.8 to ensure that Fe ³⁺ D, precipitating, separating, and performing filter pressing to obtain filter residues, namely iron slag, and enabling the filtrate to enter the step D;

D. adding sodium carbonate into the filtrate until the final pH value of the solution is 10-10.5, simultaneously reacting the sodium carbonate with manganese sulfate in the filtrate to generate manganese carbonate precipitate, performing filter pressing to obtain filter residue, namely manganese residue, and performing the filtrate in the step E;

E. and (3) sending the filtrate into an MVR evaporator for evaporation, supersaturating to separate out sodium sulfate crystals, and centrifugally separating and drying the crystals to obtain a sodium sulfate product.

2. The process for recovering tin, iron and manganese from tantalum slag elution sulfuric acid as claimed in claim 1, wherein the weight of the water added in the step A is 1.2-1.6 times of that of the tantalum slag.

3. The process method for recovering tin, iron and manganese from tantalum slag elution sulfuric acid as claimed in claim 1, wherein the weight of the water added in the step B is 1.2-1.6 times of that of the tin-containing filter residue.

4. The process method for recovering tin, iron and manganese from tantalum slag elution sulfuric acid as claimed in claim 1, wherein the tin-containing tantalum slag product in the step B contains 13% -18% of Sn and less than or equal to 0.6% of Mn.

5. The process method for recovering tin, iron and manganese from tantalum slag elution sulfuric acid as claimed in claim 1, wherein the filtrate obtained by pressure filtration in the step B is returned to the step A for recycling.

6. The process method for recovering tin, iron and manganese from tantalum slag elution sulfuric acid as claimed in claim 1, wherein the Fe content of the filter residue in the step C is 45% -55%.

7. The process method for recovering tin, iron and manganese from tantalum slag elution sulfuric acid as claimed in claim 1, wherein the Mn content of the manganese slag in the step D is 25-35%.

8. The process method for recovering tin, iron and manganese by sulfuric acid elution of tantalum slag according to claim 1, wherein the condensed water obtained by evaporation in the step E is returned to the step B for recycling.

9. The process for recovering tin, iron and manganese from sulfuric acid eluted from tantalum slag of claim 1, wherein the mother liquor obtained by centrifugation in the step E is returned to an MVR evaporator for recycling.