Leaching Treatment Method for Copper-Bearing Ores

The leaching treatment method for copper-bearing ores comprises the following steps:

1、Use ammonium sulfate as the solid-phase reactant, fully mix it with crushed and ground copper-bearing ore, and then roast the mixture;

2、Transfer the product of the above-mentioned solid-phase reaction to hot water, conduct stirring and leaching, and then perform filtration;

3、Carry out separation and purification on the filtrate according to the ore components.

Under atmospheric pressure and low reaction temperature, the above method uses ammonium sulfate as the reactant to undergo a solid-phase reaction with copper and other metals contained in the ore. Copper is then transferred (leached) into the solution via clean water, which facilitates further separation and refining and ultimately yields the target product.

The ammonia released during the ore dissolution reaction and the remaining ammonium sulfate solution after separation of the leaching solution are respectively recovered and recycled, thereby forming a self-circulation of raw and auxiliary materials within the system and minimizing the loss of ammonium sulfate. Compared with conventional treatment methods, the leaching treatment method for copper-bearing ores of the present invention has the advantages of low environmental pollution, low energy consumption, and significantly reduced production costs.

A Leaching Method for Oxygen-Sulfur Mixed Copper Ore

A leaching method for oxygen-sulfur mixed copper ore, belonging to the technical field of hydrometallurgy.

The oxygen-sulfur mixed copper ore is first ground; then it is added to an aqueous ammonium carbamate leaching agent containing an oxidant for oxidative leaching, and a copper-rich leachate can be obtained through solid-liquid separation.

This method does not require high-temperature and high-pressure equipment for the reactor; it has the characteristics of low impurity content in the leachate, low loss of leaching agent during the leaching process, easy separation of copper from impurities, low leaching production cost, and little environmental pollution.

The method is as follows:

Crush and grind the combined copper oxide ore, then mix it with water to obtain raw ore pulp;

Subject the raw ore pulp to beneficiation using the process of "low-intensity magnetic separation - gravity separation - high-gradient magnetic separation";

Combine the gravity separation concentrate and high-gradient magnetic separation concentrate obtained from the beneficiation process, filter to get enriched residue, and prepare primary pulp;

Add sodium hydroxide for pretreatment, and obtain pretreatment solution and pretreatment residue after filtration;

Prepare secondary pulp and carry out acid leaching on it to obtain copper-containing acid leaching solution.

the recovery rate of copper is no less than 80%, and sponge copper with a mass purity of not less than 90% can be obtained through further extraction. It has the advantages of high beneficiation index, high product quality, strong operability and simple process flow.

the technical field of hydrometallurgy.

The method comprises: adding 8~167 mg/L of silver sulfate, 1~12 g/L of pyrite and 1.8~36.4 g/L of sodium persulfate as a compound enhanced leaching agent for copper sulfide ore to the leaching system, so as to improve the hydrometallurgical leaching efficiency of copper sulfide ore and reduce the leaching temperature.

When the temperature is 20℃, under the combined action of the enhanced leaching agent, the leaching rate of copper sulfide ore is 8.4~12.4% higher than that of the control group without any enhanced agent added at 50℃, with the temperature reduced by 30℃.

This method enables energy-saving enhanced leaching of copper sulfide ore, improves copper leaching rate, reduces energy consumption and cuts production costs.

Stage-by-stage Heap Leaching Process for Low-grade Mixed Copper Ore

This process is designed to treat low-grade mixed copper ores containing oxidized copper ores and sulfide copper ores, and consists of the following steps:

Raw ore crushing: The raw ore undergoes three-stage one-closed-circuit crushing;

Sulfuric acid curing;

First-stage heap leaching: Heap leaching in a reusable yard;

Second-stage heap leaching: Heap leaching in a permanent yard;

Copper metal recovery: Extraction, stripping, and electrowinning processes.

Process Method for Copper Recovery from Low-Grade Copper Oxide Ore

This method enables the efficient utilization of low-grade copper oxide ore resources, and is particularly suitable for treating alkaline copper-bearing oxide ores. Its process characteristics are as follows: After fine grinding, the ore is made into pulp and subjected to leaching with added reagents. The leached pulp then undergoes four-stage thickening counter-current washing. The raffinate produced from the pregnant solution through the solvent extraction-electrowinning (SX-EW) process is recycled back to the ore grinding, pulp preparation and leaching section.

The reagents used in this process are recyclable with no net reagent consumption. Featuring a simple process flow, low production cost, this method generates favorable economic and social benefits.

Extracting Palladium from Spent Palladium Catalysts

The primary goal of recycling spent palladium catalysts is to extract palladium. Different purification methods are tailored to various types of palladium catalysts, and here we introduce the roasting and leaching purification method.

1、High-Temperature Roasting
Roast the spent palladium catalyst at high temperature. The main purpose is to remove excess impurities in the catalyst, typically organic substances and volatile gases, followed by enrichment of the spent palladium catalyst.

2、Aqua Regia Leaching
Soak supported spent palladium catalysts in aqua regia. Aqua regia, composed of hydrochloric acid and nitric acid, boasts strong dissolving capacity. It not only enhances the palladium purification rate but also dissolves other redundant base metals. After leaching, test whether the pH value meets the required standard.

3、Reduction and Separation
Filter out residual solids, collect the leachate, and pour it back into a beaker. Add a reducing agent dropwise to initiate a reduction reaction in the solution. Separate the liquid from the resulting sponge palladium, then filter and wash the sponge palladium thoroughly.

4、Melting and Quality Testing
Retrieve the sponge palladium and dry it. Transfer the dried sponge palladium into a melting crucible for smelting. After completion of melting, weigh the product, calculate the purification rate, and use spectroscopic analysis to detect the purity of the extracted palladium.

At present, the recovery and refining technologies for palladium-carbon catalysts mainly include chemical methods, physical methods and biological methods.

Among them, chemical methods cover acid-base leaching, redox process, complex extraction, etc. These methods boast merits like high recovery efficiency and straightforward operation, yet they are plagued by the challenge of difficult chemical waste disposal.

Physical methods involve pyrolysis, high-temperature oxidation and the like. They feature simple operation and low cost, but their recovery rates are relatively lower.

Among all these approaches, complex extraction stands out as a relatively promising technology. This method works by forming a composite through integrating palladium-carbon catalysts with other compounds, followed by separating palladium from the composite via chemical or physical means.

This technique not only boosts the recovery rate but also reduces environmental pollution and the volume of waste generated.

For the silver-containing catalysts used in the petrochemical and pharmaceutical industries, and the silver paste recovered from the solar energy industry, since they contain basically no other metal impurities besides silver, we have designed a new recovery process.

After such silver-containing waste catalysts and silver paste are leached with nitric acid, the pH value and silver ion concentration of the leachate are adjusted, and then it is directly transferred to a silver electrowinning cell for electrowinning treatment. The barren solution obtained after electrowinning is used as make-up water for diluting the leachate in the next batch, and the electrowon silver powder can meet the requirements of National Standard Grade 1 Silver.

The silver electrowinning process for recycling silver-containing waste catalysts boasts advantages such as simple operation and low production cost.