CN111172406A - Method for copper smelting by hydrogen-rich water wet method - Google Patents

Abstract

The invention provides a method for copper hydrometallurgy by using hydrogen-rich water. The method is mainly characterized in that alkaline hydrogen-rich water is used for reacting with copper sulfate solution obtained by a wet copper smelting process at normal temperature and normal pressure, and metal copper can be obtained by precipitation or centrifugation. The method is suitable for replacing a hydrogen autoclave and an electrodeposition process in a wet copper smelting process. The method is simple to operate, low in cost, efficient and environment-friendly, and has good environmental and economic benefits.

Description

Method for copper smelting by hydrogen-rich water wet method

Technical Field

The invention belongs to the technical field of copper smelting chemical industry, and particularly relates to a method for smelting copper by a hydrogen-rich water wet method.

Background

Copper is one of the important non-ferrous metals. The smelting method of copper is divided into two major types, namely a fire method and a wet method. The development of copper metallurgy technology goes through a long process, but the copper smelting is mainly carried out by a fire method until now, and the yield of the copper smelting accounts for about 85 percent of the total world copper yield. With the progress of the wet copper smelting technology, the proportion of copper produced by a wet process to the total output is continuously increased, and the production scale of the wet copper smelting is rapidly developed. Because the wet-process copper smelting process is simple, the cost is low, the energy consumption is low, the pollution is less, various copper ores with multiple grades can be processed, and the like, the wet-process copper smelting is more likely to be superior to the pyrometallurgy in the future.

At present, the wet copper smelting mainly comprises the following three production processes according to the copper mineral form, the copper grade and the gangue component of a copper-containing material: (1) copper sulfide concentrate-sulfating roasting-waste electrolyte leaching-leachate purification-insoluble anode electrolysis; (2) copper oxide ore and copper-containing waste rock, layered heap leaching, solution purification, organic solvent extraction, back extraction of waste electrolyte, liquid purification, and insoluble anode electrolysis; (3) oxidizing calcine of high-MgO, CaO copper oxide ore or sulphide ore, pressurizing ammonia leaching, solvent extraction, back extraction of waste electrolyte, electrodeposition to produce electrodeposited copper, or production of copper sulfate after ammonia evaporation of back extraction liquid, or production of CuO powder by direct ammonia evaporation and calcination of ammonia immersion liquid.

In either process, the intermediate product forms a copper sulfate solution. At present, the electrolytic deposition is directly carried out, or the electrolytic deposition is carried out after the organic solvent extraction and the back extraction purification, or the scrap iron is used for replacing the copper. The main problems of electrolysis technology are energy consumption and environmental impact. The environmental impact is mainly the danger and potentially harmful by-products of electrolysis (such as lead and harmful acid mist). The replacement of copper by iron filings produces waste ferric sulfate liquid, which is difficult to treat and pollutes environment.

Since the 50 s in the 20 th century, the metals such as copper, nickel and cobalt are produced by hydrogen reduction in industry, and remarkable economic benefit and social benefit are obtained. At present, the process for producing copper by hydrogen reduction must use a high-pressure kettle, and hydrogen is directly introduced to react at high temperature and high pressure. The process has the advantages of simple flow, less equipment investment, convenient operation, good product quality, higher yield, no impurity accumulation problem, basically no environmental pollution and good environmental and economic benefits, and the contents of main heavy metal ions in the discharged tail liquid are controlled within an extremely low range. The disadvantages are that not only is it necessary to invest in autoclave equipment, but the direct use of hydrogen makes the production operations dangerous and complex.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for copper smelting by a hydrogen-rich water wet method, which is simple, low in cost, high in efficiency, environment-friendly and good in environmental and economic benefits.

The purpose of the invention is realized by the following technical scheme:

hydrogen has reducing properties and the most typical reaction represented is the reduction of copper oxide by hydrogen. However, the reducibility of hydrogen must be exhibited under certain conditions, such as the reduction of copper oxide by hydrogen must be carried out under heating. The hydrogen is not activated generally under normal temperature and pressure, and the reducibility is difficult to show. Therefore, the conventional copper hydrometallurgy method using hydrogen reduction must be carried out in an autoclave. However, we have found that hydrogen gas can reduce copper ions to elemental copper even at normal temperature and pressure. However, since hydrogen is hardly soluble in water at normal temperature and pressure, it is often difficult to reduce copper ions by introducing hydrogen into a copper sulfate solution. The method adopts the alkaline high-concentration hydrogen-rich water, does not need any equipment, and can quickly reduce copper ions in the copper sulfate solution into metal copper at normal temperature and normal pressure:

Cu²⁺+H₂+2OH^-＝Cu+2H₂O

the hydrogen-rich water is alkaline after adding small amount of sodium hydroxide, so that the main products after reaction of a large amount of hydrogen molecules and copper sulfate are metal copper and sulfuric acid, and a small amount of sodium sulfate.

The method for copper smelting by the hydrogen-rich water wet method comprises the following steps:

(1) adopting corresponding wet copper smelting leaching processes according to different types of copper ores to obtain a copper sulfate solution or other copper ion-containing solutions;

(2) adding alkaline super-saturated hydrogen-rich water into copper sulfate solution or other copper ion-containing solution, standing and reacting for 30-60 min;

(3) precipitating or centrifuging to obtain metal copper, and drying to obtain copper powder;

(4) preferably, the leaching solution obtained in the step (1) is further subjected to an extraction-back extraction process to obtain a high-purity copper sulfate solution, alkaline supersaturated hydrogen-rich water is added, and after the reaction is completed, the high-purity copper metal is obtained through precipitation or centrifugation.

The invention has the beneficial effects that:

(1) the method has few steps and very simple operation;

(2) the invention uses hydrogen-rich water, which is non-toxic, harmless, residue-free and very environment-friendly;

(3) the method is carried out at normal temperature and normal pressure, does not need any special equipment, and has safe operation and low cost;

(4) the invention uses the alkaline super-saturated hydrogen-rich water and the copper sulfate solution to generate the metal copper and the sulfuric acid, and the sulfuric acid can be recycled, thereby reducing the cost and the pollution.

Detailed Description

Example 1 copper oxide ore sulfuric acid leaching-extraction-back extraction-hydrogen-rich water precipitation wet copper smelting method

Crushing copper oxide ore, controlling the granularity to be less than or equal to 20mm, stacking the ore on a mine pile field which does not leak at the bottom and has a certain natural gradient in a partition and layer-by-layer mode, stacking each layer to a layer (1-3m) with a preset height, and spraying dilute sulfuric acid solution for leaching. The spraying system equipment comprises an infusion pump, a PVC pipeline, a spray head and the like. The leaching liquid leaches copper in the ore from top to bottom in the percolation process. Leaching for several months to obtain leachate containing copper of 1-4g/L and pH of 1.5-2.5, and collecting in a liquid collecting tank. Pumping the copper sulfate in the liquid collecting pool into an extraction tank, and extracting by using oxime chelate extractant which is selective to copper. The organic phase is separated and the copper is stripped with a more concentrated sulfuric acid solution to produce a copper sulfate solution containing about 50g/L copper. The organic solvent after the back extraction is washed and then returned to the extraction process for use. Adding alkaline supersaturated hydrogen-rich water into copper sulfate solution, standing for 30-60min for reaction, precipitating or centrifuging to obtain copper metal, and drying to obtain copper powder. The main component of the supernatant is sulfuric acid which can be recycled for copper ore leaching.

Example 2 Wet copper smelting with Hydrogen-enriched Water from copper sulphide ores

The copper sulfide concentrate is leached after the conventional process, namely sulfation or semi-sulfation roasting, to obtain copper-containing leachate. And then the copper sulfate solution is obtained through the extraction and back extraction processes in the embodiment 1. Adding alkaline supersaturated hydrogen-rich water into copper sulfate solution, standing for 30-60min for reaction, precipitating or centrifuging to obtain copper metal, and drying to obtain copper powder.

Claims (4)

1. The method for copper hydrometallurgy by using the hydrogen-rich water is characterized in that the hydrogen-rich water reacts with a copper sulfate solution or other copper ion-containing solutions to obtain metal copper.

2. The method of claim 1, wherein the hydrogen-rich water is alkaline supersaturated hydrogen-rich water, that is, hydrogen concentration is 1.6ppm or more and pH is greater than 7.

3. The method of claim 1, wherein the copper sulfate solution or other copper ion-containing solution is a copper ion-containing solution obtained from an acidic or alkaline leachate of a copper hydrometallurgy process.

4. The method for hydrometallurgical copper of hydrogen-rich water according to claim 1, characterized by the following steps:

(1) adopting corresponding wet copper smelting leaching processes according to different types of copper ores to obtain a copper sulfate solution or other copper ion-containing solutions;

(2) adding alkaline super-saturated hydrogen-rich water into copper sulfate solution or other copper ion-containing solution, standing and reacting for 30-60 min;

(3) precipitating or centrifuging to obtain metal copper, and drying to obtain copper powder;

(4) preferably, the leaching solution obtained in the step (1) is further subjected to an extraction-back extraction process to obtain a high-purity copper sulfate solution, alkaline supersaturated hydrogen-rich water is added, and after the reaction is completed, the high-purity copper metal is obtained through precipitation or centrifugation.