492 results about "Cyanation" patented technology

The invention belongs to the technical field of solid pollutant treatment, and particularly relates to a method for removing cyanide in cyanidation tailings through metal activated persulfate oxidation. The problems that different cyanide removal mechanisms are different, the removal efficiency is low, the cost is high, secondary pollution is easily caused and the like exist in treatment of the cyanidation tailings. The tailings are subjected to cyanogen reduction treatment by adopting a stage treatment method. The method comprises the following steps: firstly, crushing the tailings to prepare a charcoal-loaded metal composite material Me / BC; when free cyanide in the tailings is smaller than or equal to 50 mg / kg, Me / BC activated persulfate is used for conducting cyanide reduction treatment on the tailings; when the tailings contain free cyanide gt; when the concentration is 50 mg / kg, free cyanides in the tailings are removed through leaching, and then Me / BC is used for activating persulfate to degrade strong complex state cyanides in the tailings. By adopting the method, the problems that complex cyanide is difficult to remove by a single leaching method and persulfate is large in dosage and high in cost in a single oxidation method can be solved, and the cascade cyanogen removal method is efficient, low in cost and free of secondary pollution.

The invention discloses a cyanide-free cadmium plating bath solution, a preparation method of the cyanide-free cadmium plating bath solution and application of the cyanide-free cadmium plating bath solution in cadmium plating. The cyanide-free cadmium plating bath solution comprises the following components according to the concentration: 50-70 g / L of cadmium chloride, 180-250 mL / L of an etidronic acid aqueous solution, 16-33 g / L of potassium sodium tartrate, 0.01-0.2 g / L of polyethylene glycol, 0.01-0.2 g / L of a brightener and 0.01-0.1 g / L of an additive HY. The method has the advantages that the bath solution is environment-friendly and non-toxic, wastewater treatment is simple, a plating layer is high in deposition speed, fine in crystallization and good in binding force, the problems that cyanide cadmium plating pollutes the environment, EDTA cadmium plating is poor in stability and the like are effectively solved, and the method has good application value and economic and social benefits.

The invention discloses a method for preparing a mine filling cementitious material by using cyanide tailings, comprising the following steps: weighing dried cyanide tailings, secondary aluminum ash, barium slag and phosphogypsum in proportion, and putting them into a tank mixer for mixing; after uniform mixing, adding sodium hydroxide solution for wetting, and using a tablet press to press the powder into a cubic green body, and placing the green body in an oven for drying without overlapping; putting the dried green body into a high-temperature box-type muffle furnace for calcining; adding phosphogypsum into the calcined clinker phase, crushing the green body, and sending the green body into a ball mill for ball milling treatment to obtain a cementitious material, and using tailings as aggregates, and supplemented with a polycarboxylic acid water reducer, and adding water to prepare a cementitious material for mine filling; the invention uses cyanide tailings as raw materials, and combines industrial solid wastes such as barium slag, secondary aluminum ash and phosphogypsum, and adopts a one-step activation method to prepare a cementitious material, which can simultaneously complete the decyanation and detoxification of the tailings and the activation of the tailings, has a simple process flow, and the prepared filling material has a fast hydration and hardening rate, good fluidity and high mechanical strength.

The invention provides a cyanide-containing wastewater resource recovery and cyclic utilization method, and belongs to the technical field of environmental protection and water treatment. According to the method, firstly, copper is collected through sulfuration under the weak acid condition with the pH being 5-6, so that a copper-cyanogen complex ([Cu (CN) 43-]) in wastewater is converted into a mixed material of copper sulfide (CuS) and cuprous cyanide (CuCN), and primary recovery of copper is achieved; and then, adding a pH regulator 2 to control the pH of the reaction system to be 9-11, adding a separation agent to control the ORP of the reaction system to be-400mV to-200mV, and carrying out a separation reaction. In the process, cuprous cyanide reacts with free cyanide (CN <->) to generate a soluble copper-cyanogen complex, and copper sulfide is retained, so that cuprous cyanide is accurately separated from the copper-containing material, the content of cyanide in the material is reduced, and the obtained copper-containing material meets the requirements of industrial product quality standards and pollution control standards; the problems that in the prior art, the cyanide content in the copper-containing material obtained by recycling copper from the cyanide-containing wastewater exceeds the standard, and the environmental risk is high in storage, transportation and comprehensive utilization are solved.

The invention discloses a track kiln for preparing high-strength basalt aggregate from cyanidation tailings, and relates to the technical field of solid waste recycling, the track kiln comprises a base, a track and a kiln car, the track is fixedly mounted at the top of the base, and the kiln car is internally provided with a self-propelled structure and can travel along the track; the device further comprises a side frame fixedly connected to the top of the kiln car, hollow shafts are symmetrically and fixedly connected to the inner side of the side frame, and the sides, close to each other, of the two hollow shafts are fixedly connected with center gears. Raw materials are conveyed in the form of arranging the tunnel kiln, the raw materials are contained in the trays in the conveying process, the materials move in a static mode along with the kiln car, no relative rolling exists between particles, large friction does not exist between the raw materials and between the raw materials and the conveying system, and particle shape damage caused by friction is reduced; the problems that irregular-structure raw material particles outside the raw materials are crushed or rubbed flat due to mutual friction of the raw materials, irregular forms cannot be reserved, and the mechanical property of the aggregate is affected are solved.

The invention relates to a flow battery carbon-based electrode and a preparation method and application thereof, and the preparation method comprises the following steps: respectively dissolving cobalt salt and alkali in a polar organic solvent, and uniformly mixing to form a precursor solution; placing a carbon-based material in the precursor solution, and carrying out a hydrothermal reaction to obtain a carbon-based electrode precursor; and performing high-temperature carbonization on the carbon-based electrode precursor in an inert atmosphere, cooling to room temperature after the reaction is completed, and then cleaning and removing impurities from a product to obtain the carbon-based electrode, the polar organic solvent is at least one of formamide, acetonitrile and N, N-dimethylformamide; after cobalt cyanide is deposited on the surface of the carbon-based material, surface etching and nitrogen doping are carried out on the carbon-based material under the high-temperature condition, surface modification of the carbon-based material is achieved, the contact area of the surface of the carbon-based electrode and electrolyte is increased, and the electrochemical performance of the carbon-based electrode is improved.

The utility model relates to the related technical field of filter pressing devices, in particular to a filter pressing device for cuprous cyanide waste liquid after copper sulfide precipitation, which comprises a rack and a frame fixed on the back surface of the rack, a plurality of uniformly distributed filter plates are arranged in the rack, a driving component is arranged in the frame, a mounting box is arranged at the top of the frame, and the mounting box is connected with the rack. And a fixing shaft is fixedly arranged in the mounting box, an inserting rod is arranged outside the fixing shaft in a sliding and sleeving mode, and a steering assembly and a pushing assembly are arranged in the mounting box. Through the arranged pushing assembly, when the steering assembly operates the insertion rod to be clamped with the filter plate, the pushing assembly reciprocates the insertion rod left and right, the insertion rod acts on the filter plate, and the filter plate vibrates, so that part of filter cakes which are difficult to automatically fall off in the filter plate can be shaken off, the filter plate and the filter plate do not need to be manually separated, and the labor intensity of workers is reduced. And the automatic treatment effect is achieved, and the working efficiency is improved.

The present invention provides a method for treating heap leaching cyanide tailings of gold mines, a composite bacterial community, a bacterial agent and a preparation method. The composite bacterial community comprises a TDB-1 strain, a TCD-1 strain and a Z-90 strain, wherein the TDB-1 strain is a Pseudomonas putida strain, and the deposit number is CGMCC No.21602. The TCD-1 strain is a Methylorubrum pseudosasae, and the deposit number is CGMCC NO.24728. The Z-90 strain is a Burkholderia sp., and the deposit number is CGMCC No.9970. The above-mentioned composite bacterial community can effectively remove cyanide, thiocyanide and metal-cyanide complexes. The present method has the advantages of simple operation, high reduction efficiency, stable effect, good impact resistance and low cost.

To provide a method for producing 4-ketobenzamide derivatives and 4-ketobenzoic acid derivatives.SOLUTION: The present invention provides a method for producing a 4-ketobenzamide compound represented by formula (2), by amidating a compound represented by formula (1), which is obtained through cyanation of a compound represented by formula (3), as well as a method for producing a 4-ketobenzoic acid derivative represented by formula (6), by hydrolyzing the compound represented by formula (1) or the compound represented by formula (2), and a method for producing a 4-ketobenzoic acid ester derivative represented by formula (5), by esterifying the compound represented by formula (2), wherein R1 represents a C1-C6 alkyl group or the like, R2 represents a C1-C6 alkyl group or the like, R3 represents a C1-C6 alkyl group or the like, X represents a halogen atom or the like, Y represents a C1-C6 alkyl group or the like, and n represents an integer of 0-3.SELECTED DRAWING: None

The invention provides a hydrocyanation reaction method, the hydrocyanation reaction method is carried out in a reaction system containing aromatic amine under the action of a nickel-monodentate phosphite ligand catalyst, the structure of the aromatic amine is # imgabs0 #, and X1-X3 groups and Y1-Y3 groups respectively comprise any one of hydrogen, alkyl, alkoxy, alkylamino, hydroxyl and amino. The nickel-monodentate phosphite ligand catalyst and the aromatic amine with a specific structure are used in the hydrocyanation reaction method, so that the time of the hydrocyanation reaction method can be catalytically shortened, accumulation of ligand hydrolysate can be remarkably reduced or eliminated, and the loss of the catalyst in the reaction is reduced. The hydrocyanation reaction method disclosed by the invention is high in reaction efficiency, stable in catalyst performance, high in raw material conversion rate and product selectivity, and can be used for a preparation process for preparing adiponitrile by a direct hydrocyanation method of large-mass butadiene.

The invention provides a hydrocyanation reaction method, the hydrocyanation reaction method is carried out in a reaction system containing aromatic amine under the action of a nickel-bidentate phosphite ligand catalyst, the structure of the aromatic amine is # imgabs0 #, and X1-X3 groups and Y1-Y3 groups respectively comprise any one of hydrogen, alkyl, alkoxy, alkylamino, hydroxyl and amino. The hydrocyanation reaction method is high in reaction efficiency, accumulation of ligand hydrolysate can be remarkably reduced or eliminated, and the effective content of a catalyst in a reactant is stabilized; in addition, the hydrocyanation reaction method has the advantages of high reaction efficiency, few side reactions, high raw material conversion rate and high product selectivity, and can meet the requirements of a large-scale production process for preparing adiponitrile by using a butadiene direct hydrocyanation method.

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 discloses an amidoximation hydrotalcite material as well as a preparation method and application thereof, and the method comprises the following steps: grafting and modifying an amino group on hydrotalcite to obtain an amination modified hydrotalcite material; grafting and modifying an aldehyde group on the amination modified hydrotalcite material to obtain an aldehyde modified hydrotalcite material; carrying out condensation reaction on the hydroformylation modified hydrotalcite material and a reagent containing amino and cyano groups at the same time to obtain a cyanylation modified hydrotalcite material; and carrying out amidoximation reaction on the cyanation modified hydrotalcite material and an oximation reagent to obtain the cyanation modified hydrotalcite material. The amidoximation hydrotalcite powder material prepared by the preparation method disclosed by the invention can realize high-specificity recognition and efficient adsorption on uranyl ions.

The invention relates to an efficient copper removal and recycling process for copper-cyanogen complex wastewater, which comprises the following steps: (1) critical acidification-selective crystallization of the copper-cyanogen complex wastewater: directionally recombining a copper-cyanogen complex to generate insoluble CuCN crystals by accurately regulating and controlling the pH value of the wastewater; (2) rotational flow enhanced crystallization: separating CuCN crystals from overflow liquid through a hydrocyclone; (3) gradient activation of a composite vulcanizing agent for deep copper removal: enabling the fine CuCN particles and the dissolved-state low-coordination copper-cyanogen complex to react to generate insoluble CuS crystals by adjusting the pH value and adding the composite vulcanizing agent; and (4) magnetic seed enhanced separation: carrying out magnetic separation by adopting modified magnetic seeds and a low-intensity magnetic separator, separating CuS magnetic flocs from the wastewater, and finally obtaining purified tail liquid. According to the closed-loop process, copper in the copper-cyanogen complex wastewater can be efficiently removed and recovered, the purified tail liquid can be reused for cyanidation leaching operation, the unit consumption of sodium cyanide is remarkably reduced, the leaching rate of gold and silver is increased, and zero discharge of wastewater and full recovery of copper resources are truly achieved.

The invention discloses a method for degrading gold cyanidation tailings through photo-Fenton of an aluminum-based bimetallic catalyst, and belongs to the technical field of cyanidation tailings treatment. Iron salt and zinc salt are loaded on activated aluminum oxide through an impregnation method, the aluminum-based bimetallic catalyst is obtained through the treatment processes of roasting, grinding, drying and the like, and iron oxide and zinc ferrite contained in the synthesized aluminum-based bimetallic catalyst are main active substances for degrading cyanide residues through photo-Fenton catalysis; under the participation of hydrogen peroxide and an ultraviolet light source, the concentration of cyanide in the cyanide residues can be remarkably reduced, toxicity detection on the reacted filter residues shows that the concentration of the cyanide is lower than the national standard, and the cyanide residues can be treated as general solid waste; the cyanide removal rate can reach 95% or above, and the method has a very good application prospect.

The invention provides a preparation method of a chlorantraniliprole key intermediate 2-amino-5-cyano-N, 3-dimethyl benzamide, which comprises the following steps: taking cheap and easily available o-methylaniline as a raw material, acylating an aniline substrate through Boc anhydride, carrying out ortho-lithiation on n-butyllithium, introducing carbon dioxide gas, and carrying out acid hydrolysis to obtain 2-amino-3-methyl benzoic acid, thereby obtaining the chlorantraniliprole key intermediate 2-amino-5-cyano-N, 3-dimethyl benzamide. The preparation method comprises the following steps: firstly, preparing an isatoic anhydride intermediate, then carrying out triphosgene ring closing to obtain an isatoic anhydride intermediate, carrying out bromine para-position halogenation, carrying out cuprous cyanide high-temperature Rosenmn-von Braun reaction, and finally carrying out methylamine ring opening to obtain the target product 2-amino-5-cyano-N, 3-dimethylbenzamide, and although the route is long, the yield is high, the continuity is good, few industrial three wastes are generated, and the cost is lower, so that the preparation method has great industrial production value.

The invention belongs to the technical field of organic synthesis and drug intermediate preparation, and relates to a resolution preparation method of a monepantel key intermediate. In the first aspect, the invention provides a preparation method of a compound shown as a formula 3, which comprises the following steps: # imgabs0 #, in which R1 is selected from TMS, TES, TBDMS, TIPS, TBDPS or # imgabs1 #, the reaction is as follows: # imgabs2 # comprises the following steps: step 2, reacting a compound shown as a formula 2 with an ammonia source and a cyaniding reagent to obtain the compound shown as the formula 3; according to the method 2, the reaction is as follows: # imgabs3 # comprises the following steps: step 5, a compound shown in a formula 7 is subjected to the action of ammonia gas to obtain a compound shown in a formula 3; on the second aspect, the invention provides a preparation method of a compound shown as a formula 5, and the reaction is as follows: # imgabs4, in which R1 is as described in the first aspect; the method comprises the following steps: step 3, obtaining a compound shown as a formula 5 from a compound shown as a formula 3 under the action of a resolving agent. The method disclosed by the invention is higher in yield, simpler in post-treatment and simple and convenient to operate, and has a good industrial production prospect.

The invention relates to the technical field of chemical intermediates, and particularly discloses a preparation method of a givelastat intermediate.According to the preparation method, an initiator compound 5 can be synthesized by adopting cheap 2-hydroxy-6-naphthoic acid (CAS: 16712-64-4, 141 yuan / kg), and the preparation method is different from a method in the prior art. A gemvelastat intermediate compound 4 is synthesized from a compound 5 through a three-step reaction, compared with the prior art, the yield is high, industrial amplification production is more facilitated, in the process of synthesizing a compound 6 from the compound 5, acetonitrile can be adopted as a cyanide source in a reaction system, activated hydroxyl is subjected to a coupling reaction, and the yield is high. In the process of synthesizing a compound 6 from a compound 7 instead of a traditional metal cyanide, or in the process of synthesizing a compound 6 from another compound 5, a cheap cuprous cyanide and cuprous iodide system is adopted for a coupling reaction, and in the process of synthesizing a compound 4 from a compound 7, an acetic acid and sodium triacetoxyborohydride reaction system is adopted, so that the compound 6 is synthesized. And the important intermediate of the givelastat can be obtained with high yield.

The invention discloses a method for quantitatively testing the content of organic carbon and disseminated particle size in gold ore, and belongs to the technical field of gold ore detection. The method comprises the steps of sample preparation and quantitative testing, wherein palm wax serves as a cementing agent, barite serves as a standard sample, and a to-be-tested sample is prepared through melting, mixing, consolidation, polishing and carbon spraying; the quantitative test is based on an automatic process mineralogy test system, palm wax backgrounds are removed through backgrounds deduction, an energy spectrum library is established to recognize organic carbon and barite particles, the area ratio of the organic carbon and the barite particles is measured, the mass ratio is converted by combining the density ratio, the organic carbon content of raw ore is inversely calculated, and meanwhile, the particle size distribution of the organic carbon is counted. The method solves the problem that the content and granularity of organic carbon cannot be accurately quantified at the same time in the prior art, has the advantages of high test precision, high efficiency, comprehensive parameters and simplicity and convenience in operation, and can provide key data for optimization of a gold ore cyanidation leaching process.

The invention relates to the technical field of solid-liquid separation devices, and discloses a solid-liquid separation device for recycling and treating rare and precious metals in cyaniding waste liquid, which comprises a support frame body, a separation mechanism, an anti-blocking mechanism, a liquid inlet mechanism and an exhaust mechanism, and the separating mechanism comprises a separating box body, a linear reciprocating driving assembly and a filtering sieve plate, the separating box body is installed on the supporting frame body in a sliding mode, and the driving end of the linear reciprocating driving assembly is connected with one side of the separating box body. The anti-blocking mechanism provided by the invention has two use states, when cyaniding waste liquid is filtered and separated, the anti-blocking mechanism can be used for scraping and cleaning viscous substances adsorbed on the filter sieve plate, the problem that the viscous substances in the cyaniding waste liquid block the filter sieve plate is solved, and after filtration is completed, the viscous substances in the cyaniding waste liquid can be removed by switching the other use state. And the filtering sieve plate can be rotationally cleaned, and the cleaning effect on the filtering sieve plate is improved.

The invention discloses a carbamoyl-substituted diarylethene derivative as well as a preparation method and application thereof, and the preparation method comprises the following steps: reacting R-substituted 3-bromo-2-hydroxybenzaldehyde with an arylmethyl triphenylphosphonium bromide compound or an aryl acetic acid compound to obtain an intermediate A; then the intermediate A and cuprous cyanide are subjected to a heating reaction in N, N-dimethylformamide and nitrogen atmosphere, and an intermediate B is obtained; and finally, heating the intermediate B, acetaldoxime and indium trichloride in toluene for reaction to obtain the carbamoyl-substituted diarylethene derivative. The carbamoyl-substituted diarylethene derivative disclosed by the invention has a remarkable effect in an in-vitro anti-tumor activity test, particularly has excellent anti-proliferation ability to human BRCA mutant tumor cells, and can be used for preparing medicines for treating PARP-1 activity abnormity related diseases. The synthesis route is simple, the cost is low, and large-scale implementation is facilitated.

To provide methods for producing cyano derivatives of heterocyclic compounds with sulfur-containing substituents, which act as valuable synthetic intermediates in the production of heterocyclic compounds with sulfur-containing substituents having pest control activity.SOLUTION: The present invention provides a method for producing a cyano heterocyclic compound represented by formula (2) by reacting a heterocyclic compound represented by formula (1) with a cyanating agent (3) and an iodide salt (4). The inventive method enables the high-yield production of the cyano heterocyclic compound, which is the target product, while suppressing the formation of by-products.SELECTED DRAWING: None

To provide a thermoplastic resin composition from which a resin molded article excellent in moldability, impact resistance, rigidity, weather resistance and adhesion of a deoxime type silicone-based sealing material cured product is given.SOLUTION: A thermoplastic resin composition contains a graft copolymer obtained by polymerization of a vinyl monomer containing an aromatic vinyl compound and a vinyl cyanide compound in the presence of a rubbery polymer, a vinyl-based copolymer which contains a unit derived from an aromatic vinyl compound and a unit derived from a vinyl cyanide compound, and contains no unit of formula (1), and a modified vinyl-based copolymer containing a unit derived from an aromatic vinyl compound, a unit derived from a vinyl cyanide compound, and a unit of Formula (1), and when the total of the units is 100 mass%, a content ratio of the rubbery polymer is 5 to 25 mass%, and a content ratio of the unit of Formula (1) in the modified vinyl-based copolymer is 1 to 20 mass%.SELECTED DRAWING: None

The utility model belongs to the technical field of sewage treatment, and particularly relates to a carbon fiber production wastewater treatment device. Comprising a plate heat exchanger, a polymer sedimentation tank, an air flotation machine, a hydrolysis acidification tank, an anoxic tank, an aerobic tank and a secondary sedimentation tank which are sequentially connected, an inlet of the plate heat exchanger is connected with a carbon fiber production device, and an outlet of the secondary sedimentation tank is connected to a sewage treatment plant; the system further comprises a decyanation pool, an inlet of the decyanation pool is connected with the high-concentration cyano compound wastewater collecting tank, and an outlet of the decyanation pool is connected to the hydrolysis acidification pool; an inlet of the neutralization tank is connected with the acrylic acid production device, and an outlet of the neutralization tank is connected to the hydrolysis acidification tank. By using the acrylic acid production wastewater as the composite carbon source and recovering the dry powder, the outsourcing cost of the carbon source and the sludge treatment cost are remarkably reduced; by combining the synergistic effect of physical pretreatment, chemical decyanation and biodegradation processes, cyanides, suspended solids and organic pollutants are efficiently removed, and it is ensured that the effluent index stably reaches the standard.

The present invention provides a paroxysmal hemoglobinuria indication drug ipropam key intermediate synthesis method, and relates to the technical field of ipropam, the method comprises: taking p-bromobenzaldehyde as an initial raw material, adopting an S-configuration catalyst to obtain an intermediate 03, carrying out protection group removal on the intermediate 03, carrying out automatic ring closing to obtain an intermediate 04, and carrying out post-treatment to obtain the paroxysmal hemoglobinuria indication drug ipropam key intermediate. Reducing the intermediate 04 with sodium borohydride to obtain a single cis-configuration intermediate 05, then carrying out a chiral flip reaction and hydrolysis to remove p-nitrobenzoic acid, then carrying out an etherification reaction with diethyl sulfate to obtain an intermediate 08, reducing amide of the intermediate 08 with sodium borohydride and boron trifluoride diethyl etherate to obtain an intermediate 09, then carrying out an acetylation reaction to protect amino, and finally carrying out a reaction to obtain the chiral cis-configuration intermediate 03. Cuprous cyanide is subjected to a cyanation reaction and a hydrolytic esterification reaction to obtain the ipropam key intermediate TM. The method is low in raw material price, high in chiral control selectivity, easy in reaction condition control and low in equipment requirement, avoids column chromatography and other operations, and is more suitable for industrial production.

The invention provides a harmless utilization method of cyanidation tailings, and belongs to the field of cyanidation tailings solid waste resource utilization, cyanidation tailings are used as a main raw material, municipal sludge, fly ash and a purifying agent are matched, and after mixing and roasting (in an oxygen-free atmosphere), harmless lightweight aggregate meeting the standard is obtained. According to the method, the inert gas serves as the protective atmosphere, anaerobic pyrolysis is kept in the whole roasting process, hydrocarbon gas generated in the reaction process is beneficial to formation of pores in the lightweight aggregate, and the collapse degree of the generated pores can be reduced; in this way, the release degree of harmful substances in the cyanidation tailings in the environment is effectively reduced, and pollution to the environment is reduced; in addition, valuable building materials are produced, and waste recycling is achieved. A new solution is provided for treatment of the cyanidation tailings, and development of the environmental protection industry is promoted.

The invention discloses a cyanide-free chemical silver plating stabilizer which comprises the following components in mass concentration: 10-20 g / L of 3-mercapto-2-butanol, 1-2 g / L of sodium thioglycolate, 0.1-0.2 g / L of ethyl thioglycolate and the balance of water. The cyanide-free chemical silver plating stabilizer provided by the invention adopts 3-mercapto-2-butanol, sodium thioglycolate and ethyl thioglycolate as raw materials, and has the characteristics that the raw materials are easy to obtain, environment-friendly, non-toxic and the like; meanwhile, 3-sulfydryl-2-butanol, sodium thioglycolate and ethyl thioglycolate all contain sulfydryl, the sulfydryl can effectively regulate and control the speed of reduction reaction of silver ions on a catalytic interface, and the stability of the cyanide-free chemical silver plating solution can be synergistically improved by compounding 3-sulfydryl-2-butanol, sodium thioglycolate and ethyl thioglycolate according to a certain proportion; and the chemical plating solution has the characteristics of low concentration, low use cost and the like, and is suitable for mass production of chemical plating.

The invention discloses a preparation method of a 3-thiocyano indole derivative. According to the method, indole or substituted indole is taken as a substrate, ammonium thiocyanate is taken as a reactant, N-fluorobenzenesulfonamide (NFSI) is taken as an accelerant, reaction is carried out for 0.5-3 hours at room temperature, and C3-thiocyanated indole can be obtained. The method has the advantages of easily available reaction raw materials, mild reaction conditions and short reaction time, is suitable for industrial production, and provides a new method and different reaction mechanisms for thiocyanation of the C3 site of the indole compound.

The invention relates to the field of harmless treatment of dangerous solid wastes, in particular to a harmless treatment method for mineralizing cyanidation tailings through steel slag and microorganisms, which comprises the following steps: preparing a bacterial liquid, inoculating with sporosarcina pasteurii, and culturing to prepare a microbial bacterial liquid; steel slag-cyanidation tailing slurry is prepared, specifically, steel slag and cyanidation tailings are sequentially weighed according to the proportion and mixed to be uniform, then a microbial bacterium solution, a cementing solution and water are added, the mixture is stirred to be uniform, and microbial cementing filling slurry is obtained; and underground backfilling. The prepared underground backfill slurry removes cyanide in tailings, solidifies heavy metal, is good in cementing property, can be used as an underground backfill material for backfill, provides a new solution for resource utilization of cyanidation tailings, also promotes high additional utilization of solid waste steel slag, reduces environmental influence, provides potential value, and has a wide application prospect. And sustainable development is realized.

The invention discloses a preparation method of (S)-3-aminobutyronitrile hydrochloride compounds, which comprises the following steps: S1, chlorination reaction: adding thionyl chloride and a catalyst into a reaction solvent, controlling a certain temperature, dropwise adding a compound 1, reacting at a certain temperature after dropwise adding, and dropwise adding into water for quenching to obtain an aqueous solution of a compound 2; s2, cyaniding reaction: adding the compound 2 into a reaction solvent, adding a 30% sodium cyanide solution, controlling a certain temperature, reacting for a certain time, extracting and layering after the reaction is finished, washing an organic phase with a sodium chloride solution, and concentrating to obtain a compound 5; and S3, salt forming reaction: dropwise adding a solution of an HCl (gas) organic solvent into the organic solvent of the compound 5, controlling a certain temperature, reacting for a certain time, and after the reaction is finished, cooling, filtering and drying to obtain a target compound 6. The (S)-3-aminobutyronitrile hydrochloride is obtained with the mole yield of 68.5%, the cost is low, and the cost competitiveness is very high.