阅读说明：本技术 一种从提钨后渣中高效浸出钴、镍的方法 (Method for efficiently leaching cobalt and nickel from slag after tungsten extraction ) 是由 许开华 蒋振康 杜柯 李梦予 徐阿龙 黄跃义 于 2019-09-10 设计创作，主要内容包括：本发明适用于工业废弃物资源综合回收利用技术领域,提供一种从提钨后渣中高效浸出钴、镍的方法,该方法将提钨后渣用硫酸溶液进行酸性浸出,同时加入氢氟酸作为添加剂,酸浸完毕后,经过滤实现液固分离,得到浸出渣和富集钴、镍的浸出液,浸出渣用沸水进行洗涤,然后将洗涤水返回浸出液,实现了提钨后渣中钴、镍的高效富集,本发明通过加入氢氟酸作为添加剂,有效破坏并溶解了包裹钴、镍氧化物相的二氧化硅相,强化了钴、镍的浸出反应,提高了钴、镍的浸出率和浸出效率,并有效降低了酸耗,从而降低了钴、镍的回收成本。(The invention is suitable for the technical field of comprehensive recycling of industrial waste resources, and provides a method for efficiently leaching cobalt and nickel from slag after tungsten extraction.)

1. A method for efficiently leaching cobalt and nickel from tungsten extraction slag is characterized by comprising the following steps:

s1, drying, crushing, dry-grinding and screening the slag after tungsten extraction;

step S2, under normal pressure, carrying out acid leaching on the sieved tungsten-extracted slag by using a sulfuric acid solution, and adding hydrofluoric acid as an additive;

step S3, after the acid leaching is finished, liquid-solid separation is realized through filtering, and leaching residue and leaching liquid rich in cobalt and nickel are obtained;

and step S4, washing the leaching residue obtained in the step S3 with boiling water, then returning the washing water to the leaching solution obtained in the step S3, and after the washing is finished, treating the leaching residue without toxicity by adopting a conventional method.

2. The method for efficiently leaching cobalt and nickel from the slag after tungsten extraction as claimed in claim 1, wherein in step S1, the slag after tungsten extraction is the slag after tungsten is recovered from alkaline leaching slag, the components of the slag are oxides containing cobalt and nickel, a ball mill is used for dry grinding and sample preparation and screening, and the particle size of at least 80 wt% of the slag after tungsten extraction is controlled to be smaller than 100 meshes.

3. The method for efficiently leaching cobalt and nickel from the slag after tungsten extraction as claimed in claim 1, wherein in step S2, the concentration of sulfuric acid used is 2-3 mol/L, the addition amount of hydrofluoric acid is 15-30 mL, the leaching temperature is controlled to be 80-100 ℃, the liquid-solid ratio is 4: 1-5: 1, and the leaching time is 2-3 h.

Technical Field

The invention belongs to the technical field of comprehensive recycling of industrial waste resources, and particularly relates to a method for efficiently leaching cobalt and nickel from slag after tungsten extraction.

Background

Due to over-exploitation in recent years, the period of available exploitation of the world tungsten ore is shortened rapidly, so that the recycling of secondary tungsten resources is gradually emphasized by tungsten manufacturers at home and abroad. As a main secondary tungsten resource, after the tungsten is recovered from the waste residual hard alloy, the hard alloy grinding material and the tungsten smelting slag through a main process of a molten salt roasting-water leaching method, the generated slag after tungsten extraction is still enriched with high-grade cobalt and nickel, and has a great recycling value. The currently common processes for recovering cobalt and nickel from metallurgical slag containing cobalt and nickel are divided into pyrometallurgy and hydrometallurgy. The pyrometallurgical process is mainly characterized by that it utilizes reduction smelting or reduction-sulfurization smelting, and adds reducing agent or simultaneously adds reducing agent and sulfurizing agent at high temp. to prepare cobalt-nickel alloy phase or cobalt-nickel-rich sulfonium phase, and can recover cobalt and nickel. The process has large energy consumption, and the subsequent processes of magnetic separation and acid leaching are still required, so the process line is complicated; in the hydrometallurgical process, the cobalt oxide and the nickel oxide in the slag are dissolved by using strong acid, the process line is shorter than that of a pyrogenic process, but the slag after tungsten extraction is often higher in silicon content, and the cobalt nickel oxide in the slag is often wrapped by a silicon dioxide phase, so that the acid leaching recovery rate of cobalt and nickel is lower, the acid consumption is higher, and the recovery cost is higher.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a method for efficiently leaching cobalt and nickel from slag after tungsten extraction, and aims to solve the problems of low leaching rate of cobalt and nickel, large acid consumption and high cost in the traditional cobalt and nickel hydrometallurgy recovery process.

In order to achieve the purpose, the invention provides a method for efficiently leaching cobalt and nickel from slag after tungsten extraction, which comprises the following steps:

s1, drying, crushing, dry-grinding and screening the slag after tungsten extraction;

step S2, under normal pressure, carrying out acid leaching on the sieved tungsten-extracted slag by using a sulfuric acid solution, and adding hydrofluoric acid as an additive;

step S3, after the acid leaching is finished, liquid-solid separation is realized through filtering, and leaching residue and leaching liquid rich in cobalt and nickel are obtained;

and step S4, washing the leaching residue obtained in the step S3 with boiling water, then returning the washing water to the leaching solution obtained in the step S3, and after the washing is finished, treating the leaching residue without toxicity by adopting a conventional method.

The invention has the beneficial effects that: according to the invention, hydrofluoric acid is added as an additive, so that the silicon dioxide phase wrapping the cobalt oxide phase and the nickel oxide phase is effectively destroyed and dissolved, the leaching reaction of cobalt and nickel is enhanced, the leaching rate and the leaching efficiency of cobalt and nickel are improved, the acid consumption is effectively reduced, and the recovery cost of cobalt and nickel is reduced.

Drawings

FIG. 1 is a process flow chart of the method for efficiently leaching cobalt and nickel from slag after tungsten extraction.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a method for efficiently leaching cobalt and nickel from slag after tungsten extraction, which comprises the following steps:

and step S1, extracting tungsten, and preparing a sample from the slag.

And drying, crushing and screening the slag after tungsten extraction. In this step, the slag after tungsten extraction is the waste slag after tungsten is recovered from the alkaline leaching slag (it is required to be explained that the conventional process is adopted for recovering tungsten from the alkaline leaching slag, and the detailed process is not repeated), the main components of the slag are oxides of cobalt and nickel, the oxide is dried in an oven to remove water, then a jaw crusher is used for crushing, a sample is prepared by dry grinding through a ball mill and is sieved, and the particle size of at least 80 wt% of the slag after tungsten extraction is controlled to be smaller than 100 meshes during ball milling and sieving.

And step S2, acid leaching.

And (3) carrying out acid leaching on the sieved slag after tungsten extraction by using a sulfuric acid solution under normal pressure, and adding hydrofluoric acid as an additive.

In the step, because the slag after tungsten extraction is enriched with high-grade cobalt and nickel, cobalt and nickel oxides in the slag after tungsten extraction are dissolved out by adopting sulfuric acid, and preferably, the concentration of the used sulfuric acid is 2-3 mol/L.

The content of silicon in the slag after tungsten extraction is high, and the cobalt-nickel oxide phase in the slag after tungsten extraction is wrapped by the silicon dioxide phase and can not contact with sulfuric acid, so that the acid leaching recovery rate of cobalt and nickel is low, and the acid consumption is high. Preferably, the addition amount of hydrofluoric acid is 15-30 mL.

In the step, in order to improve the leaching rate and leaching efficiency of cobalt and nickel, in the acid leaching process, the leaching temperature is controlled to be 80-100 ℃, the liquid-solid ratio is 4: 1-5: 1, and the leaching time is 2-3 hours.

And step S3, liquid-solid separation.

And after the acid leaching is finished, liquid-solid separation is realized through filtering, and leaching residues and leaching solution rich in cobalt and nickel are obtained.

And step S4, washing.

Washing the leaching residue obtained in the step S3 with boiling water for multiple times, then returning the washing water to the leaching solution obtained in the step S3, and after washing is finished, treating the leaching residue without toxicity by adopting a conventional method.

In the step, a small amount of leaching solution is carried by the leaching residues, after washing, the washing water contains cobalt and nickel, and the washing water is returned to the leaching solution obtained in the step S3, so that the waste of resources is effectively avoided.

In order to explain the technical means of the present invention, the following description will be given by way of specific examples.