In alternative embodiments, provided are methods and processes for the removal of cadmium (Cd) from wet-process phosphoric acid that may contain Cd, including excessive amounts of Cd. The process developed is based on the application of commercially available ion exchange resins with the application of Continuous Ion Exchange (CIX) technology. In alternative embodiments, provided are processes and methods for the recovery and/or the removal of cadmium from wet-process phosphoric acid using a continuous ion exchange approach. In alternative embodiments, use of processes and methods as provided herein allows for the reduction of cadmium metal contaminants with minimal phosphate losses and dilution in order to produce a phosphoric acid that is suitable for the production of fertilizers and phosphoric acid products, such as world-class diammonium phosphate fertilizer (DAP), merchant-grade phosphoric acid, super-phosphoric acid, and other phosphoric acid products.

Provided is a method for separating impurities and cobalt without using an electrolysis process from a cobalt chloride solution containing impurities and producing a high purity cobalt sulfate. The production method includes: a first solvent extraction step (S1) of bringing an organic solvent containing an alkyl phosphoric acid-based extractant into contact with a cobalt chloride solution containing impurities, and extracting zinc, manganese, and calcium into the organic solvent to separate to remove zinc, manganese, and calcium; a copper removal step (S2) of adding a sulfurizing agent to a cobalt chloride solution and generating a precipitate of sulfide of copper to separate to remove copper; a second solvent extraction step (S3) of bringing an organic solvent containing a carboxylic acid-based extractant into contact with a cobalt chloride solution and back extracting cobalt with sulfuric acid after extracting cobalt into the organic solvent to obtain cobalt sulfate solution; and a crystallization step (S4) of the cobalt sulfate solution obtained after having undergone through the second solvent extraction step (S3). These steps are sequentially executed. Without using an electrolysis process, a high purity cobalt sulfate is directly produced by separating cobalt and impurities containing manganese.

A method for collecting silver ions and phosphoric acid in a waste fluid includes collecting silver chloride from the waste fluid, collecting silver chloride including providing a chloride compound to the waste fluid; and collecting phosphoric acid, collecting phosphoric acid including distilling the waste fluid from which the silver chloride has been collected.

A method of making a polycrystalline diamond compact includes forming a first layer of polycrystalline diamond precursor materials comprising diamond particles and a first concentration of catalyst, forming a second layer of polycrystalline diamond precursor materials comprising diamond particles and a second concentration of catalyst, and placing a layer of an infiltrant material in the proximity of the first or the second layer of polycrystalline diamond precursor materials. The second concentration of catalyst is greater than the first concentration of catalyst. The infiltrant material is a catalyst. The first layer and the second layer are sintered under high-pressure high-temperature conditions in the presence of the infiltrant material to form the polycrystalline diamond compact. At least a portion of the catalyst is leached from the polycrystalline diamond compact.

A process for removal of aluminium and iron in the recycling of rechargeable batteries comprising providing a leachate from black mass, adding phosphoric acid (H.sub.3PO.sub.4) to said leachate and adjusting the pH to form iron phosphate (FePO.sub.4) and aluminium phosphate (AlPO.sub.4), precipitating and removing the formed FePO.sub.4 and AlPO.sub.4, and forming a filtrate for further recovery of cathode metals, mainly NMC-metals and lithium.

Provided is a method for producing metal microparticles in which the ratio of crystallite diameter to the particle diameter of the metal microparticles is controlled. At least two types of fluid to be processed are used, including a metal fluid in which a metal or a metal compound is dissolved in a solvent, and a reducing agent fluid which includes a reducing agent. Sulfate ions are included in one or both of the metal fluid and the reducing agent fluid. The fluid to be processed is mixed in a thin film fluid formed between at least two processing surfaces, at least one of which rotates relative to the other, and which are disposed facing each other and capable of approaching and separating from each other, and metal microparticles are precipitated. The present invention is characterized in that at this time, the ratio (d/D) of the crystallite diameter (d) of the metal microparticles to the particle diameter (D) of the metal microparticles is controlled by controlling the molar ratio of metal and sulfate ions in the mixed fluid to be processed.

Provided is a method for directly recovering lead oxide used for a lead-acid battery negative electrode from waste lead paste. The method comprises: (1) contacting waste lead paste with a barium-containing desulphurizer under desulphurization reaction conditions, and performing a solid-liquid separation on the mixture after contacting to obtain a filtrate and a filtration residue; and (2) performing a conversion reaction on the above-mentioned filtration residue at a temperature of 350-750° C. so as to convert the lead-containing components in the filtration residue into lead oxide. In the method, the direct recovery of a lead oxide raw material applicable to a lead-acid battery negative electrode from waste lead paste is achieved by quantitatively replenishing a barium sulphate additive in the process of desulphuration thereby substantially decreasing the recovery cost and energy consumption, and improving the comprehensive utilization of waste lead paste.

Provided herein are processes for recovering metal present at low concentration from an acidic aqueous solution, including contacting the acidic aqueous solution with an organic phase solution including one or more 5-(C.sub.8 to C.sub.14 alkyl)-2-hydroxyaryloxime, thereby extracting at least part of the metal from the acidic aqueous phase; increasing or maintaining the concentration of metal in the organic phase solution by recycling a portion of the organic phase solution containing the metal and contacting the organic phase with an acidic aqueous solution containing the metal; contacting the organic phase solution containing metal with an aqueous phase strip solution comprising an inorganic compound that back-extracts the metal, thereby stripping at least part of the metal from the organic phase solution to the aqueous phase strip solution; and separating the metal from the aqueous phase strip solution, thereby recovering the metal.

A process for bio-oxidation of sulfides in mineral ore having a metal such as gold occluded or dispersed within the ore as a sulfide is disclosed. The first step comminutes the ore into particles with a size distribution having a P80 of less than 0.25 inch with minus 106 micron particles in the range of 15% to 40% by weight. Agglomerates are formed by adding to the comminuted ore particles an acidic inoculate solution including water, with the solution further including microorganisms capable of bio-oxidizing the sulfides. The agglomerates are then placed in at least one bio-reactor containment vessel to form an ore bed. The process continues by bio-oxidizing the sulfides in the ore bed; then re-circulating the solution through the ore bed, and continuing the bio-oxidation until a desired bio-oxidation level is achieved. Thereafter, the metal is recovered from the ore.

A method of leaching a precious metal contained in decopperized anode slime includes, agitating and circulating a slurry at the same time, in carrying out hydrochloric acid oxidation leaching of the precious metal contained in the decopperized anode slime by adding a hydrochloric acid and an oxidant to the slurry of the decopperized anode slime, wherein in the circulating, the slurry is extracted from a lower portion of a tank and supplied again into an upper portion of the tank.