The direct electrolysis of copper sulfide ores is a method within the fields of chemistry and metallurgy. Its characteristic feature lies in the use of reduced copper chloride solutions for leaching copper ores at the anode zone, while copper deposits are simultaneously electrodeposited in the cathode zone to produce electrorefining copper that meets the GB466—82 standard.

This process can be carried out using flowable electrolytic cells, which are capable of handling single copper sulfide ores, complex copper ores, and copper sulfide ores with relatively high lead and zinc content. The production workflow is simple, with low overall energy consumption, no pollution, and ease of industrial implementation.

Method for Recycling Palladium Rhodium Alloy：

1. Solution adsorption method: The palladium rhodium wastewater is passed into multiple layers of solution adsorbers with different components for adsorption, selectively adsorbing pollutants and alkali metal ions, and finally obtaining a palladium rhodium mixture, which can be purified and recovered after further treatment. This method is low-cost and can greatly reduce ecological pollution.

2. Electrolysis method: palladium rhodium ions in waste are reduced to metal ions through electrode reactions, and then refined alloys that meet strict requirements are obtained through surface activation and metal deposition. This method can extract high-purity palladium rhodium alloys with a large processing capacity and can work continuously.

3. Horizontal furnace barite carbon reduction method: palladium rhodium waste is calcined to a certain temperature, mixed with suitable barite and carbon material, and reduced. The resulting melt mixture is extracted and separated under appropriate conditions to obtain a mixture containing palladium rhodium. This method has fast response, high output, simple process, and easy control.

rhodium compounds are added to the reaction vessel, followed by King's solution for dissolution. After the reaction is complete, high-precision filters are used for filtration. The rhodium liquid is pumped back into the reaction vessel and treated with a base for water washing. After completion of the rhodium washing, high-precision filters are again employed for filtration. The rhodium wash residue is then added to the reaction vessel and acidified for dissolution. The filtered chlororhodium solution is transferred to a tank for concentration. Subsequently, it enters an off-centered extractor for rhodium extraction. The reverse extraction liquid undergoes reduction to yield rhodium powder, which is sent to a hydrogenation unit for further processing.

After extraction of rhodium, the waste water is treated with activated carbon and pumped into storage tanks for settling. Regularly, the sludge is removed through the settler unit for water replacement.

In the King's solution dissolution process, high-concentration nitrogen oxides are collected via a condenser and fed into a tower scrubber for absorption. Gases generated from the reaction vessel (both overhead and filter residues) are collected by a hood system and treated in the tower scrubber. Additionally, alkaline waste gases from rhodium washing and leaching exhaust fumes pass through the tower scrubber for final treatment before being released. The process ensures all emissions meet environmental standards and are discharged appropriately.

The quick leaching method for gold mines involves several key steps:

Crushing and Fine Grinding: The gold ore is first crushed into small particles and then finely ground to ensure maximum surface area exposure for efficient leaching.

Slurry Formation: A mixture of bromide salts, iron salts, and acid is added to the ground ore, forming a slurry that facilitates the leaching process.

Agitation: The slurry is agitated at speeds between 100 to 800 rpm under normal temperature and pressure conditions. This step ensures that the chemical reaction between the gold particles and the leaching agents is sufficiently intensive to achieve high leaching efficiency.

Filtering and Washing: After the leaching process, the slurry is filtered to separate the gold from the residue. The residue is washed away, leaving behind the leachate (filtrate) containing the dissolved gold.

Gold Recovery: Conventional methods are employed to recover the gold from the leachate, typically involving further processing such as precipitation or electroplating to produce pure gold products.

This method boasts several advantages:

Rapid Leaching Rate: The process achieves a gold leaching rate exceeding 90% in a short time.

Simplicity: The production process is straightforward and requires minimal equipment complexity.

High Efficiency: The leaching efficiency is significant due to the optimized mixture of chemicals and agitation conditions.

Broad Applicability: This method can handle various types of gold ores, including challenging ones like high-sulfur, high-antimony carbonaceous gold ores, without requiring prior treatment of the ore.

Environmental Friendliness: The absence of harmful emissions such as sulfur dioxide or oxidized antimony makes this process eco-friendly. Additionally, the non-toxic nature of the reagents used ensures minimal impact on human health and the environment.

Overall, the quick leaching method offers a cost-effective and sustainable solution for gold extraction, particularly suited for mines with complex ore bodies.

Recycling And Utilization Of Waste Three-way Catalysts:

In general, the extraction of platinum-group metals from three-way catalyst typically involves the following steps: pretreatment (collection, shell stripping, grinding, sample preparation), group metal enrichment, extraction, purification, and reduction into metallic products. First, platinum-group metal samples are removed from the catalyst housing, crushed, ground, and sieved to an appropriate particle size for subsequent processing via either fire refining or wet refining techniques. Platinum-group metals can be enriched through mechanical enrichment or chemical pretreatment. Then, group metal extraction is performed using either fire refining or wet refining methods (with or without the enrichment stage).

The refined platinum-group metal alloy obtained from fire refining needs to undergo further chemical extraction. In this process, platinum-group metals may directly dissolve into a solution, followed by wet refining for further processing. The platinum-group metal is then separated and purified from the leaching solution and reduced into final metallic products.

The fire refining technology involves treating the waste catalytic converter catalysts with additional solvents at high temperatures to effectively separate most of the platinum-group metals from the substrate, enabling smooth extraction in subsequent steps. Fire refining techniques mainly include mercury collection methods (such as lead collection, iron collection, copper collection, and nickel-zinc collection methods). Wet refining technology employs acid-base leaching or other methods to selectively dissolve platinum-group metals or non-precious metals from waste catalytic converters, achieving the separation of platinum-group metals from non-precious metals.

The leaching method for chalcopyrite, a copper ore, falls under wet metallurgical technology and encompasses the following steps:

1、Melt the chalcopyrite with NaOH (a base) to obtain pretreated Chalcopyrite.

2、Mix the pretreated chalcopyrite obtained from step 1 with acid solutions, catalysts, and oxidizing agents for oxidative leaching, yielding copper-bearing leach solution.

The process begins with using a base to fuse the chalcopyrite, altering its crystal structure and facilitating easier copper extraction while lowering subsequent leaching temperatures. In the acid leaching phase, catalysts and oxidizing agents are added to further reduce leaching temperature, shorten leaching time, and enhance copper recovery rates. The experimental results demonstrate that this leaching method operates at 75°C with a leaching time of 2 hours, achieving a copper leaching rate exceeding 99.9%.

For different precious metal raw materials, there are different refining methods. Here are some common methods:

Acidic leaching method: Use an acidic medium to dissolve the metal, then use a reducing agent to reduce it into a metallic precipitate.

Cyanide extraction method: Use cyanide compounds to reduce metal ions into metallic precipitates.

Oxidation-reduction method: Use oxidation-reduction reactions to reduce metal ions into metallic precipitates.

Solvent leaching method: Use organic solvents to extract the metal.

Roasting method: Heat the raw material containing the metal to a certain temperature, converting the metal oxide into metal.

In summary, different raw materials require different refining methods and need to be chosen based on actual conditions.

Catalytic waste treatment methods mainly include non-solvent catalysts, solvent catalysts, and carbon carriers. Domestic production enterprises adopt different processing technologies based on material properties, primarily using calcination technology as the main process and wetting technology as a secondary process. This design, targeted at the properties of coal chemical catalytic waste materials, analyzes the advantages and disadvantages of existing processing technologies and proposes a combined process of calcination plus wetting. The process sequence includes calcination, leaching, clarification, ion exchange, dissolution, deposition of zinc, and refining of zinc.

This process employs a full dissolution technology to use ion exchange resin for adsorbing zinc, producing both a basic solution containing zinc after dissolution and sulfuric acid aluminum solution. The basic solution is further processed through coordination, deposition, calcination to produce cotton wool zinc products, while the sulfuric acid aluminum solution is sent to the municipal wastewater treatment plant for use aswater clarifying agent, achieving comprehensive utilization.

Methods for Extracting Gold from Scrap PCB Boards

There are two primary methods for extracting gold from scrap printed circuit boards (PCBs). The traditional method involves using chemical solvents to leach gold, which is known for its limitations such as small capacity, low efficiency, secondary pollution from wastewater, and the loss of other metals along with non-metal resources. 

In comparison, a new extraction method employs specialized equipment to perform physical separation. This device utilizes a innovative dry physical separation technique that involves crushing, separating, and sorting to extract metal components from scrap PCBs. Subsequently, further refining steps are conducted to recover gold from these extracted metals.