125 results about "Gold leaching" patented technology

The invention provides a gold leaching agent for treating high-carbon gold-bearing minerals and a gold leaching process, and belongs to the technical field of hydrometallurgy. According to the gold leaching agent, guanidinium thiocyanate is used as an agent main body, a hydroximic acid compound is used as a complexing synergist, and soluble inorganic salt of ferric iron is used as a competitive adsorbent. In a leaching system, guanidine thiocyanate can be decomposed to generate guanidine, sodium sulfide, sodium thiocyanate and water. Thiourea anions are converted into cyanamide under the alkaline condition, then cyanamide is slowly released and decomposed into cyanide ions, the cyanide ions are complexed with gold ions, and gold leaching is achieved. Namely, guanidinium thiocyanate has the effect of releasing the cyanide ions step by step, and slow release of the cyanide ions is realized. The gold leaching agent system does not contain cyanide (sodium cyanide, potassium cyanide and the like) and is a clean and environment-friendly agent system, and efficient leaching of gold in high-carbon gold-bearing minerals can be achieved through the synergistic effect of all functional agent components.

The invention provides a dump leaching method for improving the leaching rate of gold ore, and belongs to the technical field of mineral processing. The method comprises the following steps: firstly, separating minerals into oversize products and undersize products; mixing sodium carboxymethyl cellulose, bentonite and ferrous sulfate to obtain a mixture, and granulating the undersize product by using the mixture as a binder; and mixing the undersize product particles with the oversize product, and carrying out cyanide-free dump leaching. According to the method, through graded granulation and heap building, the problem that heap building permeability is poor due to the fact that the gold ore contains many clay minerals is solved. In the granulation stage, ferrous hydroxide colloid generated by hydrolysis of ferrous sulfate in the binder can assist ore particle agglomeration, and particle stability is enhanced; during subsequent cyanide-free dump leaching, ferrous sulfate can be used as an auxiliary reducing agent and a catalyst in a thiourea gold leaching system to promote oxidation and dissolution of gold; meanwhile, ferrous ions can adjust the oxidation-reduction potential of a system, so that the thiourea gold leaching reaction is in a more favorable potential interval, the oxidation efficiency of thiourea is improved, invalid decomposition of thiourea is reduced, and therefore the use amount of thiourea and the use amount of agents are reduced.

The invention relates to the technical field of gold leaching, in particular to a permanent magnet motor direct-driven stirring system of a gold leaching tank, which comprises a reaction shell, a driving module, a stirring module, a monitoring module and a control module, the control module obtains the specific condition in the stirring process through an image detector in the stirring process of each substance in a reaction cavity, and sends the specific condition to the monitoring module; whether the operation state of the stirring module is qualified or not is judged according to the floating sand change characterization parameter and the solute proportion characterization value, and corresponding treatment measures are adopted when it is determined that the current operation state is abnormal in time, specifically, the operation power of a permanent magnet motor is adjusted to a corresponding value according to the flow velocity difference characterization value, or the pre-tightening force of a corresponding bolt is corrected, and the operation state of the stirring module is determined to be abnormal. The operation stability of the stirring system is effectively improved, and the gold treatment efficiency is improved.

The invention relates to a gold leaching agent for a waste circuit board and a method for selectively and preferentially leaching gold. The gold leaching agent comprises carbonized sodium cyanurate, alkaline thiourea, alkaline polymeric iron, alkali, carbonate, an anionic surfactant and water. The mass ratio of the carbonized sodium cyanurate to the alkaline thiourea to the alkaline polymeric iron to the alkali to the carbonate to the anionic surfactant to the water is (0.01-5): (0.01-5): (0.1-1): (0.1-1): (0.1-1): (0.01-5): (50-100); wherein the anionic surfactant is sodium m-nitro-p-toluenesulfonate and / or sodium nitrobenzene sulfonate; by means of the gold leaching agent, gold on the waste circuit board can be effectively leached out, and the leaching rate and the reaction efficiency are both high.

The invention discloses a gold leaching process using a high-safety bromine-containing substance, and belongs to the technical field of gold extraction. According to the method, the dibromo dimethyl hydantoin and the calcium bromide are prepared into the leaching solution according to a certain proportion, efficient gold leaching is achieved by adjusting parameters such as the pH value and the leaching time under the condition of the metal ion catalyst, and the gold can be effectively adsorbed, analyzed and recycled through the leached pregnant solution. Meanwhile, bromine in the leachate is recycled through an electrochemical method, bromine is prevented from permeating into the environment, the dosage of chemicals is reduced, a complete gold leaching and chemical circulating system is constructed, the gold leaching efficiency is improved, the environmental risk is reduced, the technical applicability is expanded, and the defects that traditional liquid bromine gold leaching is large in toxicity, low in leaching rate and leaching efficiency and the like are overcome.

The invention discloses a carlin type gold concentrate in-situ self-excitation and enhanced gold leaching method which comprises the following steps: adding an oxidizing agent and an alkaline reagent into a carlin type gold concentrate ore pulp system in a continuous, slow and proper adding manner at normal temperature and normal pressure, maintaining the oxidation potential of the ore pulp system to be-600 to-15.3 mV and the pH value to be 7 to 11, and carrying out in-situ self-excitation and enhanced gold leaching on the carlin type gold concentrate; and gold-loaded sulfide minerals in the gold concentrate are subjected to in-situ oxidation in a leaching system to generate stable thiosulfate as a gold leaching agent, so that in-situ self-excitation and enhanced gold leaching of the Carlin type gold concentrate are realized. According to the method, thiosulfate is formed through in-situ self-excitation, meanwhile, gold is extracted through in-situ complexing, consumption of external thiosulfate is reduced, pretreatment is not needed in the gold leaching process, the technology is simpler, the production cost is lower, the good gold extraction rate is guaranteed, meanwhile, no special requirement for equipment is needed, and the system is more controllable.

The invention discloses an environment-friendly gold leaching agent and an application method thereof. The environment-friendly gold leaching agent is formed by mixing halate, thiosulfate and an enhancer. The application method of the environment-friendly gold leaching agent comprises the following steps that gold ore is crushed and ground, the concentration of ore pulp is adjusted to be 30%-50%, then 0.2 wt%-5 wt% of the gold leaching agent is added, the pH of the ore pulp is adjusted to be 6-12, and stirring leaching is conducted for 8-36 hours at the normal temperature and the normal pressure. The environment-friendly gold leaching agent is formed by mixing common chemical reagents, the method is simple, the gold leaching rate is high, the reagent stability is high, gold leaching can be achieved under the neutral to alkaline condition, and the method is an environment-friendly gold leaching method.

The invention relates to the technical field of precious metal recovery, in particular to a process for separating precious metal from copper-nickel smelting waste, which comprises the following steps: crushing and grading the waste, adding a sulfuric acid solution containing etidronic acid, leaching, and washing, drying and crushing filter residues to obtain a pretreated material; mixing the pretreated material with a sodium peroxide-sodium carbonate composite flux, roasting, leaching with water, and filtering to obtain a filter residue B; adding a leaching agent containing hydrochloric acid, sodium chlorate and 1, 2-cyclohexanediamine tetraacetic acid into the filter residue B according to the ratio of 1: 3-1: 5, and filtering to obtain filtrate C and filter residue C; adjusting the pH value of the filtrate C to 1.5-2.5, adding an ethanol solution of sodium N, N-diethyldithiocarbamate, precipitating, washing and calcining to obtain sponge palladium; adding ammonium chloride into the filtrate D, precipitating and calcining to obtain sponge platinum; and leaching the filter residue C by using a hydrochloric acid-chloroauric acid mixed solution containing diphenylthiourea, and replacing and calcining zinc powder to obtain crude gold. According to the process, the leaching rates of platinum, palladium and gold and the product purity are greatly improved; flux and reagent systems are optimized, consumption and energy consumption are reduced, waste liquid treatment is matched for up-to-standard discharge, and efficient resource recovery and environment-friendly cooperation are achieved.

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a pretreatment method for improving the leaching rate and the carbon adsorption rate of high-sulfur-arsenic gold ore. Comprising the following steps that the high-sulfur-arsenic gold ore is ground and then prepared into ore pulp; a green oxygen activating agent and hydrogen peroxide are sequentially added into the ore pulp, oxidation pretreatment is conducted on the high-sulfur-arsenic gold ore, ore pulp activating liquid is formed, and the green oxygen activating agent is a mixture of calcium oxide, sodium persulfate and soluble bivalent iron salt; and adding a gold leaching agent into the ore pulp activation solution, adjusting the pH value of the ore pulp to 9-12, carrying out stirring gold leaching treatment, filtering to obtain a leaching solution, and then adding activated carbon to adsorb and extract gold. According to the method, a stronger oxidation environment is provided, meanwhile, the residual concentration of arsenate radicals in the solution is effectively reduced, the leaching rate of gold and the adsorption rate of activated carbon are greatly increased, excellent oxidation performance and environment friendliness are shown, and a more sustainable high-sulfur-arsenic gold ore pretreatment process is provided.

The invention provides a low-cyanide gold leaching agent system and a dump leaching process thereof, and belongs to the technical field of hydrometallurgy. According to the method, a synergistic process of'interface activation, cyanide etching and iron precipitation inhibition 'is constructed by designing a low-cyanide gold leaching agent system. The amino acid auxiliary leaching agent adsorbs the gold surface to weaken lattice energy, so that the etching efficiency of trace cyanide ions is improved; mercapto-containing malic acid is used as a chelating agent, specific mercapto in molecules of the mercapto-containing malic acid and iron ions form an ultrahigh-stability water-soluble complex, generation of ferric hydroxide precipitates is thoroughly blocked, ferrous ions stabilized by the chelating agent are subjected to in-situ oxidation through dissolved oxygen and efficiently regenerated into potassium ferricyanide, and accumulation of free cyanogens in a solution system is eliminated; meanwhile, a chelating agent-iron complex forms a self-buffering pair, the pH of the dump leaching solution is accurately controlled, and secondary precipitation caused by local alkalization is prevented. According to the process, under the synergistic effect that the core chelating agent guarantees permeation stability and the leaching aid accelerates gold dissolution, the heap leaching period is compressed to 45 days.

The invention discloses a method for removing thiocyanate radicals in cyanide-containing wastewater, and belongs to the technical field of metal refining. The method comprises the following steps: adding concentrated sulfuric acid to adjust the pH value of cyanogen-containing wastewater to 2-3, carrying out a stirring reaction, filtering, adding sodium hydrosulfite into a filtrate, simultaneously adding concentrated sulfuric acid to maintain the pH value to 3-5, carrying out a stirring reaction, firstly introducing a sodium sulfite acidic solution into overflowed H2S and HCN gas to absorb H2S gas, and then introducing a sodium hydroxide strong alkaline solution to absorb HCN gas. Aiming at cyanide-containing wastewater subjected to acidification treatment, firstly, a strong reducing agent sodium hydrosulfite is added to reduce SCN <-> into H2S and HCN with recycling value, then H2S is absorbed, elemental sulfur is recovered, finally HCN is absorbed, CN <-> is recovered, and the method is used for cyaniding gold extraction of a gold leaching system. The absorption and separation of H2S and HCN gas are realized, the recovery of elemental sulfur and CN <-> is further realized, and other ions are not introduced into a water supply system.

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a pretreatment method for enhancing peroxide to improve the leaching rate of high-sulfur-arsenic gold ore. Comprising the following steps that the high-sulfur-arsenic gold ore is ground and then prepared into ore pulp; an oxidizing agent is added into the ore pulp, oxidation pretreatment is conducted on the high-sulfur-arsenic gold ore under the catalytic action of ultraviolet light, and ore pulp activation liquid is formed; and the pH of the ore pulp activating solution is adjusted to 9-12, a gold leaching agent is added into the ore pulp complexing solution, and stirring gold leaching treatment is conducted. According to the method, efficient oxidation of sulfide and arsenide is achieved under the mild condition through the synergistic effect of photocatalysis and chemical oxidation, the leaching rate of gold is remarkably increased, compared with a conventional peroxide oxidation method for pretreatment, the leaching rate can be increased by 10%-35%, and meanwhile the agent use amount and environmental pollution are reduced.

The invention provides a sulphide ore alkaline desulfurization and cyanidation gold leaching agent system and a method for extracting gold through the sulphide ore alkaline desulfurization and cyanidation gold leaching agent system, and belongs to the technical field of hydrometallurgy. According to the method, a ternary agent system consisting of potassium ferricyanide, low-concentration sodium cyanide and thioguanosine is constructed. An efficient'oxidation-inhibition 'synergistic system is formed between the auxiliary desulfurization agent potassium ferricyanide and the thioguanosine. The rapid and selective oxidation of potassium ferricyanide is smoothly carried out under the synergistic effect of thioguanosine, minerals are thoroughly decomposed, and the surface keeps high activity; meanwhile, due to the existence of the thioguanosine, the local microcell passivation risk and catalytic electron transfer can be eliminated more directionally. The sodium cyanide and the sodium cyanide complement each other, it is jointly guaranteed that the exposed gold can be smoothly and efficiently leached through follow-up low-concentration sodium cyanide, finally, the total consumption of reagents is reduced, environmental pollution is reduced, and meanwhile high-recovery-rate extraction of the gold in the sulfide ore difficult to treat is achieved.

The invention discloses a micro-fine particle gold ore normal-pressure alkaline leaching pretreatment method based on sodium percarbonate reinforcement, and belongs to the field of precious metal metallurgy. The method comprises the following steps: adding an oxidizing agent sodium percarbonate in batches under the condition that air is filled into ore pulp, starting to monitor the oxidation potential and the pH value of a reaction system after adding, judging that the reaction reaches the end point when the sudden drop amplitude of the oxidation potential of the ore pulp within one hour is greater than or equal to 30mV and the pH value is increased by 0.3-0.5 unit, and stopping aeration to finish pretreatment; in the segmented oxidation process, the oxidation potential is controlled within the range of + 520 mV to + 550 mV by dynamically adjusting the air charging rate. According to the basic technical scheme, the gold leaching rate reaches 86.01%, the gold leaching rate reaches up to 88.92% through the optimized technical scheme, and the utilization rate of gold ore resources is remarkably increased.

The invention provides a gold leaching agent of a compound leaching aid system and a dump leaching process, and belongs to the field of hydrometallurgy, the gold leaching agent comprises an agent main body and the leaching aid system, the agent main body is sodium cyanide, the leaching aid system comprises an oxidizing agent, an oxidation synergist and a chelating gain agent, the chelating gain agent is a furan ring-shaped hydroxamic acid compound. According to the method, the high-selectivity leaching auxiliary is designed, the components of the dump leaching agent system are regulated and controlled, and efficient gold extraction of the dump leaching process is achieved through the synergistic effect of all the components in the system. Wherein the chelating gaining agent can form a stable chelate with metal ions in a solution through a special annular structure and chelating capacity, so that the metal ions are prevented from precipitating again, gold ions in the solution are kept in a free state, further reaction of sodium cyanide is facilitated, and the leaching rate of gold is increased. Meanwhile, the aromaticity of furan rings and oxygen heteroatoms enhance the solubility and stability of the furan rings in water, and the effect of the whole leaching process is improved.

The invention provides a clean gold leaching agent system for treating gold-bearing minerals and a gold leaching process, and belongs to the technical field of hydrometallurgy. According to the clean gold leaching agent system for treating the gold-bearing minerals, on the basis that thiosulfate serves as a gold leaching agent main body and metal cupric salt serves as a catalyst, a leaching auxiliary agent replacing ammonia, amine and ammonium is designed. In the gold leaching process, the leaching auxiliary agent and bivalent copper ions are subjected to chelation reaction at first, a copper-chelation product has moderate dissolving performance under the alkaline condition, the gain catalysis effect on gold leaching of thiosulfate is achieved, meanwhile, overflow of ammonia gas is avoided, and the leaching efficiency is improved. Clean extraction of gold in the gold-bearing minerals by the thiosulfate leaching system is achieved, a series of problems that in the prior art, the gold leaching effect is poor, ammonia gas overflows in the gold leaching process and the like due to the fact that copper ions of a copper ammonium system are converted into precipitates are solved, and a potential alternative scheme is provided for the field of hydrometallurgy of gold ores in the gold industry.

The invention discloses a selective gold extraction process by a thiosulfate method, which comprises the following steps of: adding gold ore and anion exchange resin into an aqueous solution of a leaching agent, and stirring and leaching to obtain ore pulp containing gold-loaded resin; the leaching agent comprises thiosulfate, copper salt and ammonia water; separating the gold-loaded resin from the ore pulp, and desorbing the gold-loaded resin by adopting a desorption agent to obtain a gold-rich desorption solution; and adding dithionite into the gold-rich desorption solution for reduction to obtain an elemental gold product. According to the process disclosed by the invention, resin adsorption and recovery are synchronously realized during gold leaching, and coadsorption of copper is avoided, so that gold can be enriched by adopting the gold-loaded resin through one-section desorption, and the gold extraction process flow is greatly simplified. In addition, the process is high in gold leaching rate, short in leaching time, low in agent consumption and low in leaching cost. In addition, the resin can be directly and circularly used for gold leaching without regeneration, the reduction barren solution can be circularly used for desorption of the gold-loaded resin by supplementing a small amount of desorption agent, and the recovery cost is low.

The invention provides a gold extraction method for carbon-containing refractory gold ore, and belongs to the technical field of hydrometallurgy. The carbon-containing refractory gold ore is placed in an electrolytic bath containing electrolyte, the pH of ore pulp is adjusted to be larger than 2 and smaller than or equal to 7, voltage is applied to an electrode, and electrochemical oxidation pretreatment is carried out. And then, the pH value of the ore pulp is adjusted to be larger than or equal to 1 and smaller than or equal to 2, anion resin is added, stirring and gold leaching are conducted, and efficient recovery of gold is achieved. According to the method, through electrochemical oxidation pretreatment, oxidation removal of carbon can be effectively achieved, and the gold robbing performance of carbon on gold is eliminated. And meanwhile, acid leaching and recycling of gold in the pretreated gold ore are successfully achieved, the acid-base transformation step of oxidizing slag is reduced, and non-cyanide leaching of gold is achieved. According to the method, gold in the carbon-containing refractory gold ore can be efficiently recycled, the technological process is short, operation is easy and convenient, environment friendliness is achieved, and a valuable technical scheme is provided for the field of precious metal hydrometallurgy.

The invention provides a method for positioning the same particle before and after gold leaching, and belongs to the technical field of particle positioning analysis. According to the method, the heavy sand sample is obtained through manual reselection; removing sulfide to obtain a gold mineral monomer; uniformly mixing the resin 1, the curing agent 1, gangue mineral particles and different pigments, and respectively adding the mixture into grinding tools with different shapes; after the resin is cured, gold minerals are selected to be placed in molds of different shapes; and uniformly mixing the resin 2 and the curing agent 2, adding the mixture into a mold, grinding and polishing to obtain exposed gold mineral monomer particles, and observing the surface phenomena before and after gold leaching under a stereomicroscope and a scanning electron microscope through different colors and shapes respectively for experimental research on the gold leaching effect of the gold leaching agent. According to the method, gangue mineral particles with different colors are introduced into the resin, so that the same gold mineral can be found more quickly after each test, the phenomena presented before and after leaching of the gold mineral are detected, and the method has guiding significance on experimental research of the gold leaching agent.

The invention relates to an environment-friendly gold leaching agent and a gold leaching method, and belongs to the technical field of gold leaching. The environment-friendly gold leaching agent comprises sodium cyanurate and guanidine salt. The gold leaching agent provided by the invention has a good gold leaching effect, is high in gold selectivity, does not contain traditional highly toxic sodium cyanide, is small in environmental pollution, and is green and environment-friendly.

The application discloses a method for improving recovery rate of extremely fine-grained gold ore by multi-process cooperation and belongs to the field of gold leaching by a wet method.According to different occurrence states of the extremely fine-grained gold ore, the application sequentially carries out phased and targeted recovery in the order of flotation, magnetic separation, alkali leaching pretreatment and cyanide leaching, or sequentially carries out phased and targeted recovery in the order of alkali leaching pretreatment, cyanide leaching, cyanide breaking, flotation and magnetic separation.Through the multi-process cooperative process, the application realizes phased and accurate recovery of gold in different occurrence states in the extremely fine-grained gold ore, significantly improves the total recovery rate of gold, and has the advantages of mild process, controllable cost and good environmental protection, thereby providing a new technical scheme for efficient recovery of extremely fine-grained refractory gold ore and having a wide industrial application prospect.

The invention discloses a preparation method of a melamine-based low-toxic gold leaching agent, belonging to the field of hydrometallurgy. First, urea, sodium carbonate and ferrous chloride are mixed evenly and finely ground; then the finely ground material is placed in a high-temperature heating container, heated gradually and kept warm after the temperature is raised; then the reaction product is gradually cooled to room temperature along with the furnace; finally, the reaction product is broken and ground into powder to obtain the melamine-based low-toxic gold leaching agent. The synthetic raw materials of this gold leaching agent are simple and cheap and easy to obtain, the synthesis process is simple and easy to control, and the synthesis cost is low. The gold leaching agent obtained by the invention has low toxicity, fast gold leaching speed, high gold leaching rate, and the leaching tailings are general solid wastes and are easier to handle.

The invention discloses a method for green and efficient recovery of gold from refractory gold ore. The green and efficient gold recovery method for the refractory gold ore comprises the following steps that biological oxidation pretreatment is conducted on the refractory gold ore, and biological oxidation ore pulp is obtained; adjusting the pH value of the biological oxidation ore pulp, standing for 1-3 days to carry out bacterial inactivation on the biological oxidation ore pulp, then adding a proper amount of iron-based ligand to adjust the potential of the biological oxidation ore pulp to a proper range, and then adding a proper amount of thiosulfate to carry out in-situ leaching to obtain leached ore pulp; and the leaching ore pulp is filtered and separated, and gold leaching liquid and leaching residues are obtained. According to the method for green and efficient gold recovery from the refractory gold ore, a biological oxidation pretreatment method and a weakly acidic iron-based thiosulfate in-situ leaching process are combined, acid-base conversion of ore pulp is not needed, and green and efficient leaching of gold in the refractory gold ore can be achieved with the low production cost and the short process.

The application discloses a gold leaching method for pyrite-containing gold ore, and comprises the following steps: after the pyrite-containing gold ore is finely ground, water is added to obtain a slurry; a gold leaching reagent solution is added into the slurry to obtain a mixed leaching solution; the pH value of the mixed leaching solution is adjusted to alkaline, and leaching treatment is performed; and after filtration, a gold-containing leaching solution is obtained; the gold leaching reagent solution comprises polyphosphate, copper salt and thiosulfate; in the gold leaching reagent, polyphosphate is added; under alkaline conditions, polyphosphate ions can be selectively adsorbed or complexed on the surface active sites of pyrite to form a physical or chemical masking layer, thereby effectively blocking the direct contact of pyrite with dissolved oxygen and thiosulfate in the solution, inhibiting the catalytic decomposition of pyrite, significantly reducing the invalid consumption of thiosulfate, stabilizing the pH value and potential of the leaching system, and guaranteeing the efficient leaching of gold.

This application provides a method for extracting gold resources from urban minerals based on TEMPO electrocatalysis-histidine gold leaching reagent system, which belongs to the technical field of precious metal recycling. This method utilizes the original copper / iron impurities in discarded printed circuit boards to construct a Cu 2+ / Fe 3+ TEMPO redox coupled synergistic catalytic system. 2+ (E°=0.34 V vs SHE) and Fe 3+ (E°=0.77 V) with TEMPO + (E°=0.75 V) forms a step-by-step electron transport chain. TEMPO is precisely controlled by electric field + The electron transfer efficiency of the TEMPO redox couple (E° = 0.75 V vs. SHE) significantly increases the gold dissolution rate while reducing energy consumption and achieving a low impurity co-dissolution rate, enabling efficient and selective recovery of gold resources from electronic waste. This invention, through the TEMPO electrocatalytic-histidine chelation synergistic system, achieves efficient and selective extraction of gold from urban minerals, fundamentally addressing the key challenges of traditional cyanide-free gold extraction processes, such as high oxidant consumption, poor selectivity, and low efficiency.

The invention provides a method for extracting gold resources in urban mineral products based on a TEMPO electro-catalysis-histidine gold leaching agent system, and belongs to the technical field of precious metal recycling. According to the method, original copper / iron impurities in the waste printed circuit board are utilized, and a Cu < 2 + > / Fe < 3 + >-TEMPO redox coupling concerted catalysis system is constructed. A stepped electron transport chain is formed by Cu < 2 + > (E < degree > = 0.34 V vs SHE) and Fe < 3 + > (E < degree > = 0.77 V) which are generated in situ and TEMPO < + > (E < degree > = 0.75 V). The electron transfer efficiency of TEMPO < + > / TEMPO redox on SHE (E degree is equal to 0.75 V vs. SHE) is precisely regulated and controlled through an electric field, the dissolution rate of gold is remarkably increased, meanwhile, energy consumption is reduced, the impurity co-dissolution rate is low, and efficient selective recovery of gold resources in electronic waste is achieved. By means of the TEMPO electro-catalysis-histidine chelation synergistic system, efficient selective extraction of gold in urban mineral products is achieved, and the key problems that in a traditional cyanide-free gold extraction process, the consumption of an oxidizing agent is large, selectivity is poor, and efficiency is low are fundamentally solved.

The present invention discloses a method for eliminating the influence of associated calcium iron pyroxene in thiosulfate leaching process, and belongs to the field of hydrometallurgy. The specific process of the present invention is to first place the associated calcium iron pyroxene gold mine in a pretreatment solution containing sodium hydroxide, ammonium bifluoride or a mixture of the two and a mixture of sodium fluoride and acid for stirring pretreatment. Then, the treated mineral is placed in a copper ammonia thiosulfate solution for leaching, so as to reduce the consumption of thiosulfate and improve the leaching rate of gold in the associated calcium iron pyroxene gold mine; the present invention effectively solves the problem that thiosulfate leaching of the associated calcium iron pyroxene contained in the gold mine causes high thiosulfate consumption and low leaching rate of gold; it has the advantages of simple process, easy control, efficient gold leaching, etc.

The invention belongs to the technical field of metallurgy, and relates to a multi-stage circulation gold extraction method for high-carbon-arsenic-sulfur gold and silver concentrate, which comprises the following steps: (1) grinding and oxidizing; (2) direct cyanidation; (3) roasting and oxidizing; (4) leaching gold with acid; and (5) cyaniding and gold leaching. The direct cyanidation-roasting oxidation-cyanidation gold extraction process is provided for the micro-dip dyeing type carbon-containing, high-arsenic and high-sulfur difficult-to-treat gold and silver concentrate, gold and silver dissociated from monomers are recycled through the first-stage direct cyanidation process, sulfide wrapping gold and carbonaceous matter wrapping gold are thoroughly oxidized through the second-stage roasting oxidation process, and gold and silver are separated from the gold and silver through the first-stage direct cyanidation process. And in the third stage, high-acid acid leaching-cyaniding is adopted to extract gold and silver, the problem of gold extraction of carbon-containing, high-arsenic and high-sulfur triple difficult-to-treat gold and silver concentrate is solved, and the method has the advantages of being high in gold and silver recovery rate, high in production efficiency, low in comprehensive cost, easy to industrialize, short in production period, environmentally friendly and the like.

In embodiments herein, a surface finish (SF) is formed on conductive contacts of a package substrate for connection to an embedded interconnect bridge circuit module die. In some embodiments, the SF may be electroless nickel plating and electroless palladium immersion gold (ENEPIG). In other embodiments, SF may be gold leaching electroless palladium leaching (IGEPIG). In other embodiments, the SF may include an electrolytic palladium gold layer on the indium layer or on the ferrocobalt layer.

The invention discloses a method for improving the recovery rate of ultra-micro-fine particle disseminated gold ore through multi-process cooperation, and belongs to the field of wet gold leaching. According to different occurrence states of the ultra-fine particle gold ore, staged and targeted recovery is sequentially carried out according to flotation, magnetic separation, alkaline leaching pretreatment and cyanidation leaching. Or sequentially performing staged and targeted recovery according to alkaline leaching pretreatment, cyanidation leaching, cyanide breaking, flotation and magnetic separation. According to the method, by means of a multi-process collaborative process, staged accurate recovery of gold in different occurrence states in the ultra-fine particle gold ore is achieved, the total recovery rate of gold is remarkably increased, the process is mild, the cost is controllable, the environmental protection property is good, a new technical scheme is provided for efficient recovery of the ultra-fine particle gold ore difficult to treat, and the method has wide industrial application prospects.