1145 results about "Sodium bisulfate" patented technology

A well dispersed oxygen scavenging particulate compounded in a polymer matrix. The oxygen scavenging formulation consists of iron powder with a mean particle sizes within 1-25 um and pre-coated with at least one or more activating and acidifying powdered compounds, usually in the form of solid organic and inorganic salts of alkaline and alkaline earth metals such as sodium chloride and sodium bisulfate. The pre-coated iron particulate is dispersed into a polymer resin by using a conventional melt processing method such as twin-screw extrusion. The oxygen scavenging compound is mixed with polymer pellets in the solid state prior to melting. The polymer resin pellets and the coated iron powder are preferably treated with a surfactant in the dry state to help dispersing the iron / salt powder with the resin pellets. The melt extruded compounds are pelletized and kept in the dry state to prevent premature activation.

The present invention is a solid rinse aid composition and methods of making and using the same. The solid rinse aid composition generally includes sodium sulfate and urea as solidification agents and an effective amount of an alcohol ethoxylate compound sheeting agent component and an effective amount of defoamer component. The solid rinse aid composition may also incorporate a preservative system including sodium bisulfate. The solid rinse aid composition may be phosphate-free, aminocarboxylate-free, and GRAS if desired.

Process for producing sodium bicarbonate for purifying flue gases, according to which an aqueous solution containing sodium sulfate is subjected to electrodialysis to produce a sodium hydroxide solution and a sodium bisulfate solution, the sodium hydroxide solution being carbonated in order to obtain sodium bicarbonate.

A massive body, e.g., a tablet, for producing a solution of chlorine dioxide when the massive body is added to liquid water. The massive body comprises a metal chlorite such as sodium chlorite, an acid source such as sodium bisulfate and a source of free halogen such as the sodium salt of dichloroisocyanuric acid or a hydrate thereof. The concentration of free halogen in the solution will be:(a) less than the concentration of chlorine dioxide in said solution on a weight basis and the ratio of the concentration of chlorine dioxide to the sum of the concentrations of chlorine dioxide and chlorite anion in said solution is at least 0.25:1 by weight; or(b) equal to or greater than the concentration of chlorine dioxide in said solution on a weight basis and the ratio of the concentration of chlorine dioxide to the sum of the concentrations of chlorine dioxide and chlorite anion in said solution is at least 0.50:1 by weight.

The present invention discloses a cyclic process for the production of taurine from ethylene oxide in a high yield of greater than 95% by continuously converting the byproducts of the ammonolysis reaction, sodium ditaurinate and sodium tritaurinate, to sodium taurinate. The cyclic process is completed by using sulfur dioxide or sulfurous acid to neutralize sodium taurinates to recover taurine and to regenerate sodium bisulfite, which is then reacted with ethylene oxide.

The Breviscapine infusion preparation is compounded with Breviscapine as main component, glucose or sodium chloride, propylene glycol, L-arginine, sodium bisulphate, EDTA-2Na and water for injection through certain technological process. The preparation is suitable for great dosage application clinically to avoid cross infection caused by intermediate links. In addition, the present invention is clear and stable.

The invention discloses compound amino acid injecta, which contains arginine hydrochloride, histidine monohydrochloride, leucine, isoleucine, lysine hydrochloride and the like; meanwhile, the invention further discloses a preparation method of the compound amino acid injecta (18AA); in the event of ensuring the product quality, the compound amino acid injecta has the characteristics of saving energy and enhancing efficacy; by means of repetitive verification on precision, detection limit, quantitation limit, linear range and the like, a simple, convenient, rapid and reliable method with cleaning verification is ensured; furthermore, the residual quantity of antioxygen, namely sodium hydrogensulfite, in the compound amino acid injecta and sulphate ion generated by degrading sodium hydrogensulfite are detected according to an ion chromatography principle, thus, the amount of the antioxygen charged in the raw material proportioning can be accurately measured, and the stability of the raw material proportioning process is judged according to the measurement result; and a detection method of the compound amino acid injecta provided by the invention is an online derivative amino acid content measuring method, the speed is rapid, and the method is applied to large-scale detection.

The invention discloses a preparation method of copper nanoparticles with different particle diameters and relates to a metal nanoparticle. The invention provides a preparation method of copper nanoparticles with different particle diameters, which has simple, economic, environment-friendly process. The preparation method comprises the following steps: adding metal salt of copper chloride or copper acetate, a solvent, a protective agent, a complexing agent and a surfactant in a vessel in sequence, and stirring to obtain a mixture, wherein the protective agent is polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, or the like, the complexing agent is oleic acid, hexadecylamine, oleamide, or the like, and the surfactant is hexadecyl dimethyl ammonium bromide, sodium dodecyl benzene sulfonate or the like; adding a reducing agent in the mixture for reacting, wherein the reducing agent is ascorbic acid, sodium formaldehyde sulphoxylate, sodium borohydride, or the like; cooling the reactant till the temperature is below 40 DEG C, then adding a precipitating agent, mixing, and centrifugally separating; then washing with the organic solvent, centrifugating, and extracting the precipitate; and then drying the precipitate to obtain red powder copper nanoparticles with different particle diameters.

The invention relates to a grafted copolymerized cationic polysaccharide bioflocculant and a preparing method thereof. A product with the cationic degree (DC) of 3-63% is finally prepared through an aqueous solution polymerization technology with a present nonionic polysaccharide bioflocculant (Dx) as a raw material, one or more of dimethyl diallyl ammonium chloride (DMDAAC), methacryloxyethyltrimethyl ammonium chloride (DMC), acryloyloxyethyltrimethyl ammonium chloride (DAC), dimethylaminoethyl methacrylate (DMAEMA), dimethylaminoethyl acrylate (DMAEA) as a monomer, and one or two of ammonium persulfate / sodium bisulfate and dibenzoyl peroxide (BPO) (AIBA) as an initiator. The preparation method is simple, and is easy to control, and the product obtained in the invention has good flocculation effect and high treatment efficiency, and can be widely used in the field of treatment various sewages, the sludge dewatering field and the like.

The invention discloses a water-reducing slump-retaining type polycarboxylic acid water reducing agent and a preparing method thereof. The water-reducing slump-retaining type polycarboxylic acid water reducing agent has the pH of 6.0-7.0 and comprises the following raw materials in parts by weight: 190-200 parts of methyl-2-buten-1-ol polyoxyethylene ether with the molecular weight of 600-3000, 15-25 parts of acrylic acid, 1-5 parts of hydroxyalkyl acrylate, 0.1-3 parts of unsaturated phosphate, 0.5-5 parts of unsaturated alcohol ether, 1.0-3.5 parts of an oxidant, 0.1-2 parts of a reductant, 0.1-2 parts of sodium formaldehyde sulfoxylate, 0.5-2.5 parts of a chain transfer agent, 325 parts of water, and a proper amount of a caustic soda liquid with the mass concentration of 30-32%. The water-reducing slump-retaining type polycarboxylic acid water reducing agent has the advantages of high content of effective components, good dispersion and excellent performance; and the preparation method adopts a room temperature process and a composite initiation system, has the appropriate reaction temperature of 5-40 DEG C, has no need of heating, makes the production more convenient and the cost lower, saves energy and protects the environment.

The invention provides a polyethyleneimine jelly profile-control water-blocking agent. The profile-control water-blocking agent is prepared by reacting partially-hydrolyzed polyacrylamide and a cross-linking agent polyethyleneimine. The profile-control water-blocking agent comprises following components by weight: 0.3-0.8% of the partially-hydrolyzed polyacrylamide, 0.2-0.5% of the cross-linking agent polyethyleneimine and 0.3-0.8% of an additive, with the balance being water, wherein the partially-hydrolyzed polyacrylamide adopts anionic polyacrylamide, and the additive is one compound selected from a group of sodium sulfite, sodium bisulfate, and sodium hyposulfite or thiourea, or is a mixture of several compounds selected from the group. The jelly forming time of the profile-control water-blocking agent is adjustable and the jelly has high strength. The profile-control water-blocking agent can block underground water having a temperature lower than 110 DEG C and a NaCl mineralization degree of 50000 mg / L. The profile-control water-blocking agent has good temperature toleration and cannot be dehydrated for 120 days.

The invention relates to a textile water-based pigment printing binding agent and a preparation method. The textile water-based pigment printing binding agent is prepared in a way that acrylonitrile, ethyl acrylate, butyl acrylate, crylic acid, hydroxyethyl methacrylate, acrylamide, sodium dodecyl sulfate, alcohol dodecyl polyoxyethylene (10) ether, deionized water, ammonium persulfate and sodiumhydrogen sulfite are subjected to emulsion polymerization and then are mixed with pyrolysis closed polyurethane crosslinking agent according to proportion. The product is cured in low temperature condition, has remarkable advantages in the aspects of dry rubbing fastness, wet rubbing fastness, soaping fastness and the like, is simple and easily-controllable in production operation, and is energy-saving and environment-friendly.

The invention discloses a water resistant whiting emulsion pressure sensitive adhesive synthesis method, and a water resistant whiting emulsion pressure sensitive adhesive comprises the following components by weight: 20-60% of a soft monomer; 1-40% of a hard monomer; 1-5% of an emulsifier and the balance of water. The emulsifier is selected from allyloxy nonylphenol propanol polyoxyethylene ether ammonium sulfate, allyloxy nonylphenoxy propanol polyoxyethylene ether ammonium sulfate, allyloxy nonylphenoxy propanol polyoxyethylene ether, and a mixture of allyloxy nonylphenol propanol polyoxyethylene ether ammonium sulfate, allyloxy nonylphenoxy propanol polyoxyethylene ether ammonium sulfate and allyloxy nonylphenoxy propanol polyoxyethylene ether. The method comprises the following steps: (I) mixing the emulsifier and the monomer basically without stirring; (II) adding part of an initiator at 78 to 82 DEG C into a reaction kettle with water, adding dropwise the monomer mixture, after addition of the monomer mixture for 30 minutes, adding dropwise the remaining initiator solution for 2 to 5 hours, controlling the reaction temperature at 80-85 DEG C, and performing thermal insulation for 0.5 to 1 hour; and (III) after thermal insulation, reducing the temperature to 50 to 70 DEG C, adding tert-butyl hydroperoxide and methylsodium hydrosulfite aqueous solution, continuing to react for 0.2-1 hour, and adjusting the emulsion pH value to 6-8 when the temperature is reduced to 40 to 50 DEG C.

The present invention discloses petroleum exploration well-drilling liquid used non-blooming anti-collapse and anti-falling filtration agent, which is confected by coal gangue 500Kg, waste orlon thread 270Kg, sodium hudroxide 100Kg, formaldehyde 20Kg, sodium nitrite 30Kg, sodium bisulfate 30Kg, phenol 50Kg, and water 3000Kg. The cost of the processing raw material of the product of the present invention is low, compared with the same kind of the product, the cost of the well-drilling slurry can be lowered by 30 percent, during the well-drilling process, the using volume is less, in the fresh water, 1 percent volume can be added, in the sea water, 3percent volume can be added, the performance is better than the performance of all the lignite resin products, the circumference of the drilling tool can form smooth and hard filtration cake to prevent the well wall from collapsing, to control the mudstone and the clay shale from swelling by absorbing water, to control the water lost volume, so as to improve the well-drilling schedule. The raw material adopted by the present invention is all non-blooming material, which has no interference to geological log, the product petroleum field is large in demand volume, and great in market potential. The present invention also discloses the preparation method for above anti-collapse and anti-falling filtration agent.

A dry disinfectant composition for the production of aqueous solutions of chlorine dioxide of predetermined concentration is formulated of a mixture of lithium hypochlorite, sodium bisulfate and sodium chlorite. Special liquid and dry formulations are also contemplated for convenience of use, for quality assurance and for safety.

The invention discloses a method for regenerating a positive electrode active material in a LiNi1 / 3Co1 / 3Mn1 / 3O2 waste lithium ion battery. The method includes the steps that the waste lithium ion battery is subjected to discharging and dismantling or positive pole leftover materials and positive electrode fragments are collected to obtain waste positive plates, and the waste positive plates are subjected to roasting, water dissolving and filtering to obtain waste LiNi1 / 3Co1 / 3Mn1 / 3O2 powder; the waste LiNi1 / 3Co1 / 3Mn1 / 3O2 powder and sodium pyrosulfate are roasted after being mixed according to a certain proportion, roasted products are leached by water, then a sodium carbonate solution is added into liquor, filtering is conducted, after the proportion of Li, Ni, Co and Mn in carbonate modulation filter residues is supplemented, the Li, Ni, Co and Mn are subjected to ball milling, compressing and roasting, and accordingly the LiNi1 / 3Co1 / 3Mn1 / 3O2 positive electrode material is obtained again. Components of filter liquor are adjusted through sulfuric acid, crystallization processing is carried out, and then sodium hydrogen sulfate is obtained.

The invention discloses a method for recovering cobalt lithium metal from a waste lithium ion battery of a lithium cobalt oxide positive material. The method comprises the following steps: discharging and disassembling the waste lithium ion battery to obtain a waste positive plate, roasting the waste positive plate, dissolving with water and filtering to obtain waste lithium cobalt oxide powder; mixing the waste lithium cobalt oxide powder and sodium hydrogen sulfate according to a certain proportion and then roasting; leaching the roasting product with water; adding sodium carbonate solution into the solution and then filtering; supplementing a certain quantity of lithium carbonate into filter residue and then performing ball milling, pressing and placing in a resistance furnace to roast to newly obtain the lithium cobalt oxide positive material with good electrochemical performance, wherein the ingredients of the filter liquor are adjusted by using sulfuric acid and the sodium hydrogen sulfate obtained after the crystallization treatment is performed can be reutilized.

The invention relates to a lost circulation material for effectively plugging fractured and crushed stratum malignant loss in the drilling process and a preparation method. The invention adopts the technical scheme that a raw material for preparing the lost circulation material comprises the following components: 8 to 12 grams of hexadecyl dimethyl allyl ammonium chloride, 16 to 18 grams of acrylamide, 6 to 12 grams of styrene sodium sulfate, 0.2 to 0.4 gram of sodium dodecyl benzene sulfonate, 0.2 to 0.4 gram of potassium persulfate / sodium bisulfite, 16 to 20 grams of bentonite clay, and 239 to 279 grams of fresh water. The preparation method of the lost circulation material comprises the following steps of: firstly, dissolving recrystallized hexadecyl dimethyl allyl ammonium chloride, acrylamide and styrene sodium sulfate in the water; filling N2, adding an initiator and performing the reaction for 24 hours; precipitating, soaking and drying by using acetone so as to obtain white copolymer; and adding sodium dodecyl benzene sulfonate and bentonite clay into the copolymer and the water to obtain the lost circulation material. The lost circulation material can be used for plugging a leakage zone, has strong crushing resistance and strong temperature resistance and mineralization resistance degree and is suitable to be used for carrying out plugging on a big crack in the drilling process.

The invention discloses stereospecific synthesis of beta-artemether by using artemisinin as a raw material through a one-pot method, which comprises the following steps of: in a system of alkaline solution of dichloromethane, taking sodium borohydride as a reducing agent and aluminium tert-butoxide as a catalyst, and reducing to obtain dihydroartemisinin; and separating out a water phase, adding methanol, sodium acid sulfate, aluminum perchlorate nonahydrate, nickelousperchlorate and the like serving as catalysts for methyl etherification, and reacting at room temperature for 2 hours to obtain the beta-artemether, wherein the maximum yield rate of the beta-artemether is 85 percent and the maximum total yield rate of artemether is 93.5 percent. The method has the characteristics of low cost, high yield, short time and simple and safe operation, and is completely suitable for industrial production.

The invention discloses an acrylate copolymer emulsion, and belongs to the technical field of aqueous coatings. The acrylate copolymer emulsion comprises, by weight, 450-550 parts of deionized water, 1-2 parts of an anionic surfactant, 5-8 parts of a reactive emulsifier, 3-15 parts of hydroxypropyl acrylate, 50-160 parts of methyl methacrylate, 20-75 parts of butyl acrylate, 200-410 parts of styrene, 5-10 parts of methacrylic acid, 3-10 parts of an adhesion function monomer, 2-9 parts of a cross-linking monomer, 3-10 parts of a cross-linking agent, 0.1-3 parts of an antifoaming agent, 0.8-2 parts of an initiator, 3-5 parts of ammonia water, 0.8-2 parts of an antiseptic, 0.1-1 part of tert-butyl hydroperoxide and 0.1-0.8 parts of sodium bisulfate. The invention also discloses an aqueous industrial anticorrosive coating adopting the acrylate copolymer emulsion as a film forming substance. The coating has the advantages of high adhesion to a substrate, high water resistance and high salt spray resistance.

The invention discloses a graphene oxide composite polycarboxylate water reducer, which is characterized by being prepared from the following raw materials and ingredients in percentage by mass: 0.1 to 2 percent of graphene oxide, 25 to 40 percent of methyl allyl polyethenoxy ether, 1.5 to 4 percent of acrylic acid, 2 to 5.4 percent of maleic anhydride, 50 to 70 percent of water, 0.4 to 1 percent of oxidizing agent of ammonium persulfate and 0.1 to 0.2 percent of reducing agent of sodium hydrosulfite. The monomer methyl allyl polyethenoxy ether, the acrylic acid, the maleic anhydride and the graphene oxide are uniformly mixed and take polymerization reaction under the initiation effect of the oxidizing agent and the reducing agent, so that the graphene oxide composite polycarboxylate water reducer is obtained. The graphene oxide composite polycarboxylate water reducer has the advantages that the dispersibility of the graphene oxide in concrete application can be effectively improved; under the condition of achieving the same intensity improving effect, the consumption of the graphene oxide in the concrete application can be reduced; the mechanical property of concrete is further improved.

The invention belongs to the technical field of methods for preparing polycarboxylic acid water reducers. A method for preparing a polycarboxylic acid water reducer comprises the following: a step 1 of esterification, in which a poly(ethylene glycol methyl ether)acrylate macromonomer is synthesized by using methoxy polyethylene glycol and acrylic acid in a molar ratio of 1:1.1 to 1:1.5 at 100 to 120 DEG C, water is separated out in a reaction process, and the molecular weight of the macromonomer is 1,250 to 3,000; and a step 2 of polymerization, in which aqueous solution of the macromonomer is prepared, an unsaturated monomer and a catalyst A are added in turn at 40 to 50 DEG C, the temperature is kept constant at 28 to 40 DEG C, aqueous solution of anhydrous sodium hydrogensulfite or vitamin c is dripped, the concentration of a solid content is kept between 35 to 45 percent by adjusting water content, stirring is stopped, and the solution is allowed to stand for 1 to 1.5 hours, the pH value is kept between 6 and 8 by alkaline reagent after the reaction is finished, and the catalyst A is peroxyacetic acid or potassium peroxydisulfate. The invention has the advantages of low cost, simple process and high product performance.

The invention pertains to a device for generating aqueous chlorine dioxide solutions when the device is contacted with liquid water. The device comprises an alkali metal or alkaline earth metal chlorite, e.g., sodium chlorite, and a chemical reagent comprising an acid or a material capable of releasing an acid upon exposure to liquid water, e.g., sodium bisulfate. The chlorite and the reagent are either combined as a mixture or are disposed as separate components adhered to the surface of one or more substrates. Upon exposure to liquid water, the chlorite and the reagent produce boundary layers. The chlorite and the reagent are disposed upon, and adhered to, the surface(s) of the substrates in a manner such that upon exposure to liquid water, the chlorite boundary layer comes into contact with the reagent boundary layer to thereby produce an aqueous chlorine dioxide solution.

The invention relates to a temperature-resistance drilling fluid drill-feeding plugging agent and its preparation method, the drill-feeding plugging agent comprises the following components by weight: 30-80 parts of vegetable fiber, 10-40 parts of mineral fiber, 10-40 parts of fruit shell, 0-10 parts of powdered steatile, and 3-10 parts of silicon-based gel deformation particles. The silicon-based gel deformation particles enable emulsification and dispersion of 1.4-2.5 parts of vinyltriethoxysilane monomer according to weight to an aqueous solution composed of 18-24 parts of acrylamide, 0.0025-0.005 parts of N,N'-methylene bisacrylamide, 0.7-1.25 parts of OP-10 and 0.1-0.17 parts of sodium dodecyl benzene sulfonate, 0.003 parts of disodium ethylene diamine tetraacetate, 0.009-0.12 parts of ammonium persulfate and 0.009-0.012 parts of sodium bisulfate, a process of micellar copolymerization is carried out, a polymer is dried, granulated and crushed to obtain the silicon-based gel deformation particles with average particle size of 80-200 meshes; easy-leakage highly-permeable stratum and micro crack are effectively plugged, rheological parameter of the drilling fluid is not influenced, frictional resistance coefficient of the drilling fluid is reduced, a storage layer is protected, and the drill-feeding plugging agent is suitable for plugging the easy-leakage stratum and the storage layer.

The invention discloses a slump-retaining water-reducing polycarboxylic acid water reducing agent and a low-temperature quick preparation method thereof. The preparation method comprises the following steps: mixing 100 parts of unsaturated polyethenoxy ether, 1-10 parts of unsaturated carboxylic acid, 0.05-2 parts of oxidizer and 40-90 parts of water, regulating the reaction temperature to 15-60 DEG C, and dissolving by stirring; simultaneously dropwisely adding a solution B containing a reducer sodium formaldehyde sulfoxylate and a solution C containing a chain-transfer agent, and after 5-30 minutes, starting dropwisely adding a solution A containing unsaturated carboxylic acid, wherein the dropwise addition of the three solutions is finished within 1-3 hours, and the finishing time of the solution B and solution C is 10-30 minutes later than that of the solution A; and keeping the temperature to react for 30-60 minutes, adding 1-10 parts of sodium hydroxide into the reaction solution to obtain the slump-retaining water-reducing polycarboxylic acid water reducing agent. By controlling the dropwise addition time and sequence of the materials and carrying out high-efficiency polymerization reaction by using the novel mixed reducer, the reactant conversion rate is higher. Compared with the existing water reducing agent, the water reducing agent disclosed by the invention has the advantages of higher slump retaining property, higher water reducing rate, higher workability and wider adaptability.

The invention relates to the technical field of building material admixtures, in particular to a room-temperature preparation method for a high-efficiency polycarboxylic acid water reducing agent. The preparation method adopts methyl allyl polyethenoxy ether and acrylic acid as reactive monomers, and adopts hydrogen peroxide as an oxide agent and sodium formaldehyde sulfoxylate as a reducing agent to build an oxidation-reduction system. The specific synthetic method comprises the following steps: adopting methyl allyl polyethenoxy ether, hydrogen peroxide and deionized water as a base solution; dropwise adding a water solution A of acrylic acid and a chain transferring agent, and a water solution B of sodium formaldehyde sulfoxylate; enabling radical polymerization reaction at room temperature. The preparation method can be carried out for synthesis at the room temperature, and is economical, environment-friendly, low in energy consumption and simple in preparation technology, and the synthesized water reducing agent is high in water-reducing rate, good in fluidity and good in slump retaining performance.

A novel water treatment method for boiler feedwater of the invention comprises the following steps: sterilization, that is adding liquid chlorine, sodium hypochlorite or stabilized chlorine dioxide into a raw water tank, controlling the residual chlorine amount in water to be 0.2-0.5 mg / L; filtration, that is adding a polyaluminium chloride coagulant before a multimedium filter with an amount of 10-20 mg / L, controlling the water turbidity of the ultrafiltration feedwater to be not more than 0.1 NTU and the SDI to be not more than 3; adding a reducing agent of sodium bisulfite before ultrafiltration with an adding amount of 3-5 mg / L; reverse osmosis, that is performing desalination treatment by a reverse osmosis membrane device, continuously adding a PTP-0100 scale inhibitor before a security filter with an adding amount of 3-5 mg / L; continuously adding a Micro Treat BIO bactericide with an adding amount of 3-5 mg / L; additionally adding cleaning agents of Dimamite and High Flux once a month with an amount of 3-5% of the water amount to be produced; desalination, that is performing desalination by an electrical desalination system (EDI); deoxygenation, that is performing deoxygenation by a vacuum deoxygenator, adding 10-20 microgram / L of deoxidants, controlling the agent residual amount to be 5-20 microgram / L, adding a corrosion-inhibiting pH regulator to control the pH value to be 8.8-9.3.

The invention provides a method for extracting refined gold from palladium-silver-containing anode mud, relates to the field of noble metal wet metallurgy, and particularly relates to a method for purifying the gold from the palladium-silver-containing anode mud. The method mainly comprises the following steps: adding the palladium-silver-containing anode mud into hydrochloric acid and carrying out chlorination dissolving; carrying out temperature rising type chlorine removing on filtered parting liquid; then adding dimethylglyoxime to carry out palladium sedimentation and impurity removal; after reaction is finished, carrying out precision filtering, wherein filtrate is gold raw liquid; introducing choline into the gold raw liquid and increasing electric potential; when the electric potential is up to more than 1000mV, stopping the introducing of the choline; adding a saturated sodium hydrogen sulfite solution into the gold raw liquid and reducing; when the electric potential is up to 620mV-630mV, stopping the reducing; and filtering after cooling, and further recycling valuable metal from the filtrate, wherein a filter cake is reduced gold powder. According to the process, the impurity palladium removing rate is high, the valuable metal can be comprehensively recycled, a flow structure is simple and the cost is low. When dimethylglyoxime is used for carrying out palladium sedimentation operation, the reaction is environmentally-friendly; and toxic and harmful gas is not generated and the reaction is rapid and efficient.

The invention relates to a preparation method of a filtrate loss reducer used for drilling fluids. With lignite as the main material, the method first prepares a sulfonated phenol-urea-formaldhyde resin mixture, which is then reacted with an alkaline solution and lignite, thus obtaining a sulfonated phenol-urea-formaldhyde resin modified lignite filtrate loss reducer. The lignite filtrate loss reducer comprises the following reactants by weight: 10%-20% of lignite; 2%-4% of one of or a mixture of NaOH and KOH; 50%-60% of water; 2%-5.5% of phenol; 8%-15% of formaldehyde; 3%-7% of urea; 0.15%-2% of a hydrolyzed acrylonitrile sodium salt; 0.125%-0.5% of polyacrylamide; and 2%-7% of a sulfonating agent (one of or a mixture of sodium sulfite, sodium bisulfite, and sodium metabisulfite).