37 results about "Sodium cyanate" patented technology

The utility model discloses a sodium thiocyanate anti-caking stock bin which comprises a bin body with a discharging port formed in the bottom, a feeding port and a mounting hole are formed in the top of the bin body, a dehumidification device is arranged in the mounting hole and comprises a filter screen, a sealing plate, a motor, auger blades and super absorbent resin particles, the sealing plate is in flange connection with the mounting hole, the filter screen is of a cylindrical structure, and the motor is connected with the motor. The top of the filter screen is fixedly connected with the lower surface of the sealing plate, the motor is installed on the sealing plate, the auger blade is located in the filter screen, the outer diameter of the auger blade is smaller than the diameter of the filter screen, the motor drives the auger blade to rotate, and the super absorbent resin particles are located in the filter screen. The moisture absorbent is arranged to adsorb moisture in the bin body, and the problem that sodium thiocyanate absorbs water and hardens is prevented.

The present application provides a copper-sulfur separation combined inhibitor and a flotation method for copper sulfide ore, and relates to the field of mineral flotation inhibitors. The raw materials of the copper-sulfur separation combined inhibitor include: sodium cyanate, sodium cyanurate and sodium carbonate; the mass ratio of the sodium cyanate, the sodium cyanurate and the sodium carbonate is (5-7): (1-3): 1. The copper-sulfur separation combined inhibitor can replace the traditional lime inhibitor, realize the environmental protection and efficient recovery of copper-sulfur resources, and overcome the various disadvantages of using lime as an inhibitor, such as the sticky foam resulting in low copper concentrate grade, calcium corrosion of pipelines and equipment, high pH value of tailings water and environmental pollution.

A process for beneficiating a sulphide ore comprising one or more sulphide minerals into at least one value mineral-rich froth concentrate is provided. The process includes subjecting an aqueous slurry or pulp of particles of the sulphide ore, in the presence of a depressant selected from the group consisting of cyanuric acid trisodium salt (C3H4N3NaO3), sodium cyanate (NaOCN), cyanuric acid (C3H3N3O3), and mixtures of two or more of these, to froth flotation by aerating the slurry or pulp thereby to produce at least one value mineral-rich froth concentrate and an aerated slurry or pulp that includes gangue. Said at least one value mineral-rich froth concentrate is then separated from the aerated slurry or pulp.

The invention provides an anti-permeability and anti-sulfate corrosion additive for organic nano concrete, and belongs to the technical field of concrete. The additive disclosed by the invention contains ethylenediamine methylene sodium phosphate, sodium polyacrylate, sodium thiocyanate, polylactic acid-glycolic acid copolymer (PLGA), hydroxypropyl ethanolamine, a modified nano graphite material, chitosan quaternary ammonium salt, a silane coupling agent, nano volcanic ash powder and other components in a specific proportion. Wherein the modified nano-graphite material is prepared by modifying nano-graphite powder with polyether amine and a silane coupling agent; all the components are matched and the additive is prepared by adopting a special preparation method, and the additive has good impermeability and sulfate corrosion resistance when being used in concrete, and is stable and reliable.

The invention relates to a flotation separation method for refractory mixed lead-zinc ore. The method comprises the steps of lead preferential flotation, lead-zinc bulk flotation, lead-zinc separation flotation and zinc flotation, and a novel sphalerite combined inhibitor composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate is added during lead-zinc separation flotation. The method realizes efficient recovery of compact dip-dyed and fine vein dip-dyed symbiotic complex refractory mixed lead-zinc ores, and has wide industrial application and popularization prospects.

The application discloses a method for preparing 2,6-dimethoxy-4-amino pyrimidine in a microchannel, and the method comprises the following steps: taking 2,4,6-trichloropyrimidine as raw material, and reacting with a sodium methoxide solution in a microreactor to obtain a methanol solution of 2,6-dimethoxy-4-chloropyrimidine; after post-treatment, 2,6-dimethoxy-4-chloropyrimidine is dissolved in toluene to obtain a toluene solution of 2,6-dimethoxy-4-chloropyrimidine; the toluene solution is reacted with a mixed solution of sodium cyanate, methanol, a palladium catalyst, a ligand and toluene to obtain (4,6-dimethoxypyrimidin-2-yl) methyl tert-butylcarbamate; and then, the (4,6-dimethoxypyrimidin-2-yl) methyl tert-butylcarbamate is reacted with hydrochloric acid to obtain 2,6-dimethoxy-4-amino pyrimidine. Compared with a traditional synthesis route, the method has the advantages of simple synthesis, simple operation, high yield, and no need of using highly toxic and high-risk materials, and the synthesis steps are greatly shortened by adopting a continuous synthesis mode of a microreactor.

The utility model discloses a sodium thiocyanate continuous production device which comprises a base, a feeding port is formed in the upper portion of the base, a screen is arranged between the feeding port and a discharging baffle, a fixing seat is arranged on the base, a first pressing frame and a second pressing frame are arranged on the fixing seat, the first pressing frame and the second pressing frame are both connected with the fixing seat in a sliding mode, and the first pressing frame and the second pressing frame are connected with the base in a sliding mode. A fixing block is arranged below the fixing seat, a sliding rod is arranged in the base, a spring is connected to the sliding rod in a sleeving mode, a cam is arranged on the base, two sets of symmetrically-distributed fixing frames are arranged on the base, and cleaning brushes are arranged on the fixing frames. The winding rod, the expansion roller and the like are matched with the first pressing frame and the second pressing frame to achieve timing transmission conversion of the screen, so that it is guaranteed that the screen is in the maximum filtering efficiency state when filtering sodium thiocyanate for a long time, and continuous production and production efficiency of sodium thiocyanate are guaranteed; and a worker does not need to regularly stop the production work of sodium thiocyanate to replace the screen.

The invention relates to the technical field of methyl isocyanate, in particular to a methyl isocyanate preparation method based on a dimethyl sulfate route, which comprises the following steps: raw material preparation: raw materials comprise sodium cyanate, orthodichlorobenzene and dimethyl sulfate, the mass ratio of sodium cyanate to dimethyl sulfate is 1: (0.6), and the mass of orthodichlorobenzene is 3-5 times that of sodium cyanate; the method comprises the following steps: raw material pretreatment: respectively pretreating sodium cyanate, o-dichlorobenzene and dimethyl sulfate for later use; according to the method, uniform slurry is formed through grinding, the specific surface area of sodium cyanate particles is increased, full contact between the sodium cyanate particles and dimethyl sulfate is promoted, the effect of improving the reaction efficiency is achieved, after heating and negative-pressure dehydration treatment, hydrolysis of dimethyl sulfate and hydrolysis side reaction of methyl isocyanate can be prevented through reduction of moisture, and therefore generation of impurities is reduced, and the product quality is improved. The product purity is improved, the product is prevented from being decomposed or subjected to secondary reaction at high temperature due to lower rectification temperature, and the product stability is ensured.

The embodiment of the invention discloses a preparation method of acrylic isocyanate ester, which comprises the following steps: reacting substituted or unsubstituted acrylic acid as shown in a formula I with bromoethanol under the action of acid to obtain an intermediate mixture, and reacting the intermediate mixture with sodium cyanate under the action of a catalyst to prepare the acrylic isocyanate ester as shown in a formula II. According to the embodiment of the invention, the bromoethanol is used as a raw material to react with the substituted or unsubstituted acrylic acid, and then reacts with the sodium cyanate under the action of the catalyst to prepare the isocyanate acrylate with different substituent groups, so that the method is simple in process, low in equipment requirement, environment-friendly in material, low in cost, high in yield and suitable for large-scale industrial production.

The invention discloses an environment-friendly gold extraction agent which comprises the following raw materials: sodium cyanurate, sodium sulfate, sodium citrate and iron carbide. Wherein the mass content of sodium cyanurate is 65%-75%, the mass content of sodium sulfate is 15%-25%, the mass content of sodium citrate is 5%-9%, and the mass content of iron carbide is 1%-5%; the method has the advantages that the leaching rate is high, and meanwhile, the safety and environmental hidden dangers in the transportation, storage or use process can be reduced.

The present invention relates to the field of metal surface treatment technology, in particular to a method for improving the surface performance of metal parts by salt bath composite nitriding treatment, specifically a salt bath composite nitriding treatment process for a high wear-resistant and high fatigue shaft pin. The process includes the following steps: 1) pretreatment: sandblasting and polishing the shaft pin to Ra≤0.8μm; 2) salt bath composite nitriding treatment: immersing the shaft pin in a salt bath containing sodium cyanate, potassium cyanate, sodium carbonate, lithium carbonate and additives, and keeping it at 560°C for 2-4 hours; 3) cooling and strengthening treatment: slowly cooling after dynamic cooling to 500°C, combining oxidation treatment and low-temperature tempering to release residual stress. The process forms a dense nitriding layer and a micro-boronization layer through the synergistic effect of rare earth oxides and fluorides, so that the surface hardness of the shaft pin reaches HV800-1100, and the depth of the nitriding layer is 0.1-0.3mm, which significantly improves wear resistance, fatigue life and corrosion resistance, and is suitable for surface strengthening of high-load mechanical parts.

The invention relates to the technical field of salt extraction and recovery of sodium-process desulfurization waste liquid, in particular to a method and device for extracting product-grade sodium thiocyanate from sodium-process desulfurization waste liquid, and the method comprises the following steps: step a, primary decoloring treatment, step b, primary concentration crystallization, step c, secondary decoloring treatment, step d, freezing crystallization, step e, precise desalting, and step f, secondary concentration crystallization. A stepped process design of two-time decoloration, fractional crystallization and precise desalination is adopted, aiming at the physicochemical property difference of three core salts of sodium sulfate, sodium thiosulfate and sodium thiocyanate in the sodium-process desulfurization waste liquid, efficient separation is realized by accurately controlling process parameters, the sodium sulfate is preferentially separated out by utilizing the characteristic that the solubility of the sodium sulfate is relatively low at high temperature, and the sodium thiosulfate is separated out by utilizing a high-temperature crystallization method. The sodium thiocyanate is separated out in a targeted manner on the premise of ensuring that the sodium thiocyanate is in an unsaturated state, so that the technical problem that the sodium thiocyanate is easy to co-crystallize at low temperature is solved.

This invention relates to the field of oilfield chemical technology, and discloses a low-molecular-weight, high-viscosity ternary polymer flooding agent, its preparation process, and its application. The low-molecular-weight, high-viscosity ternary polymer flooding agent comprises the following raw materials by weight: simulated formation water: 986.2-995.9 g; sodium thiocyanate: 0.2-1.2 g; partially hydrolyzed polyacrylamide: 1.0-3.0 g; dodecyl hydroxypropyl sulfobetaine: 2.0-6.0 g; sodium salicylate: 0.9-3.6 g. The simulated formation water is prepared from deionized water, sodium chloride, calcium chloride, and magnesium chloride. Sodium thiocyanate is added to the simulated formation water to obtain a basic conditioning fluid; partially hydrolyzed polyacrylamide is added to obtain a polymer-based fluid; dodecyl hydroxypropyl sulfobetaine is added to obtain a mixed solution; and sodium salicylate is added to induce a rheological property transformation. This invention constructs a double interpenetrating network structure, solving the problems of insufficient viscosity enhancement and poor plugging.

The invention discloses a magnesium alloy gold plating method with triple electrochemical protection effects and a plating layer structure. The process comprises the following steps: sequentially preparing a chemical zinc deposition layer, a cyanide-free copper-tin alloy plating layer, a cyanide-free copper-zinc alloy plating layer, a bright nickel-copper alloy plating layer, a nickel-phosphorus alloy plating layer, a gold plating layer and an anti-discoloration protective film on a magnesium alloy substrate. According to the cyanide-free copper-tin alloy plating process, 18-24 g / L of polycuprous thiocyanate, 0.2-0.6 g / L of stannous oxalate, 130-170 g / L of polysodium thiocyanate, 20-30 g / L of sodium 1-hydroxyethylidene-1, 1-diphosphonate and 8-12 mL / L of a copper-tin alloy plating brightener are adopted, the pH value of a plating solution is 12-13, the temperature of a plating tank is 30-40 DEG C, the cathode current density is 0.5-1.5 A / dm < 2 >, the cathode movement speed is 3-5 m / min, oxygen-free electrolytic copper particles serve as an anode, the copper particles are loaded into a titanium anode basket, the area ratio of the anode to the cathode is larger than 3: 1, and the anode movement speed is 3-5 m / min. And the surface of a plated part is not rusted after the plated part is subjected to an acetate mist test for 200 hours according to the GB / T 10125-2021 standard.

The invention relates to a continuous synthesis process of 1-(2-chlorphenyl)-3-(1-methyl-1-phenylethyl) urea, and relates to the technical field of organic synthesis.The continuous synthesis process comprises the following steps that o-chlorobenzyl chloride serves as an initial raw material, a continuous reaction device I is filled with sodium cyanate, o-chlorobenzyl chloride is added for a reaction, and reaction liquid is obtained; and introducing the reaction liquid into a continuous reaction device II to react with alpha, alpha-dimethyl benzylamine, and transferring into a continuous reaction device III to perform curing reaction, thereby obtaining the 1-(2-chlorphenyl)-3-(1-methyl-1-phenylethyl) urea. The o-chlorobenzyl chloride serving as an initial raw material is changed into o-chlorobenzylamine without an amino substitution reaction and directly reacts with sodium cyanate to obtain o-chlorobenzyl isocyanate, so that the use of highly toxic phosgene in a traditional process is avoided, the synthesis steps are few, a multi-stage tubular filler reactor is adopted, efficient continuous production is realized, and the product has high yield and purity.

The present application relates to a kind of environmental protection type gold dipping agent and gold dipping method, belong to gold dipping technical field;The environmental protection type gold dipping agent includes sodium cyanate and guanidine salt.The gold dipping agent provided by the present application has good gold dipping effect, high gold selectivity, and does not contain traditional toxic sodium cyanide, has little environmental pollution, and is green and environmentally friendly.

This invention belongs to the field of gold extraction agent technology, specifically relating to a method for preparing a gold extraction agent. The invention provides a method for preparing a gold extraction agent, comprising the following steps: mixing sodium cyanate and iron powder, and carrying out a melt catalytic reaction to obtain the gold extraction agent. This invention uses iron powder as a catalyst, which can effectively promote the polymerization reaction of sodium cyanate. During the catalytic polymerization process, iron atoms can break the carbon-nitrogen triple bond in sodium cyanate into a carbon-nitrogen double bond, with one end of the carbon-nitrogen double bond linked to a sodium atom. The obtained gold extraction agent does not contain free cyanide ions and is therefore non-toxic. In application, the sodium in the obtained gold extraction agent can displace gold in gold ore, thus playing a role in gold refining. Test results from the embodiments show that the gold extraction efficiency of the gold extraction agent provided by this invention is comparable to that of sodium cyanide, and it is safe, environmentally friendly, and non-toxic.

The invention discloses a magnesium alloy nickel plating process with triple electrochemical protection effects and a plating layer structure. The process comprises the step of sequentially preparing a chemical zinc deposition layer, a cyanide-free copper plating layer, a cyanide-free copper-tin alloy plating layer, a cyanide-free copper-zinc alloy plating layer, a bright nickel plating layer and an anti-discoloration protective film on a magnesium alloy matrix. According to the cyanide-free copper-tin alloy plating process, 18-24 g / L of polycuprous thiocyanate, 0.2-0.6 g / L of stannous oxalate, 130-170 g / L of polysodium thiocyanate, 20-30 g / L of disodium 1-hydroxyethylidene-1, 1-diphosphonate and 8-12 mL / L of a copper-tin alloy plating brightener are adopted, the pH value of a plating solution is 12-13, the temperature of a plating tank is 30-40 DEG C, the cathode current density is 0.5-1.5 A / dm < 2 >, the cathode movement speed is 3-5 m / min, oxygen-free electrolytic copper particles serve as an anode, the copper particles are loaded into a titanium anode basket, the area ratio of the anode to the cathode is larger than 3: 1, and the anode movement speed is 3-5 m / min. And the surface of a plated part is not rusted after the plated part is subjected to an acetate mist test for 96 hours according to the GB / T 10125-2021 standard.

The invention belongs to the technical field of cement additives, and discloses a high-dosage industrial waste residue cement mineralization activity activator, which comprises a grinding aid and a mineralization enhancer, the grinding aid comprises bio-based alcohol amine, molasses, alpha-olefin sodium sulfonate and water; the mineralization enhancer comprises sodium thiosulfate, sodium thiocyanate, sodium formate and calcium sulfite type desulfurized gypsum. The cement mineralization activity exciting agent is applied to a cement grinding section, a grinding aid and a mineralization enhancer are synchronously doped, and the grinding aid and the mineralization enhancer form a synergistic superimposed effect, so that the technical problem of low 3d strength of cement is solved, and the strength of each age is stably improved by exciting the early hydration activity of the cement and a mixed material.

A method for synthesizing a stable isotope-labeled toltrazuril-D3 belongs to the field of organic synthesis technology. This method uses methylamine hydrochloride-D3 as the stable isotope labeling source, reacting it with p-trifluoromethylthiophenol and 1-chloro-2-methyl-5-nitrobenzene as starting materials, undergoing sequential condensation and reduction to obtain an aminodiphenyl ether intermediate. Simultaneously, methylamine hydrochloride-D3 reacts with sodium cyanate to generate methylurea-D3, which then reacts with carbonyl diimidazole to obtain an activated intermediate. Finally, the aminodiphenyl ether intermediate condenses with the activated intermediate, followed by base-catalyzed cyclization to obtain the target product, toltrazuril-D3. This invention features a rationally designed synthetic route, readily available raw materials, mild reaction conditions, simple operation, and easy product separation and purification. The obtained product achieves a chemical purity and isotope abundance of over 99%.

The invention discloses a cleaning agent for online descaling. The cleaning agent is prepared from the following raw materials in parts by weight: 10 to 15 parts of modified microcline, 6 to 10 parts of octanol polyoxyethylene ether, 4 to 7 parts of sodium thiocyanate, 3 to 6 parts of sodium humate, 8 to 12 parts of modified tourmaline, 8 to 12 parts of deionized water and 2 to 4 parts of silane coupling agent KH560. According to the cleaning agent for online descaling, the octanol polyoxyethylene ether, the sodium thiocyanate and the sodium humate are matched with the modified microplagioclase and the modified tourmaline, balance improvement of the cleaning efficiency and the boiler corrosion protection performance of the obtained cleaning agent is achieved through blending and synergistic effects of the raw materials, and meanwhile the cleaning agent is remarkable in corrosion resistance and heat-resistant stability effect.

The invention discloses a rapid drying device for sodium thiocyanate and a using method, and relates to the technical field of drying equipment, the rapid drying device comprises a bottom plate, a drying box, a sealing side plate, an air heater, a sliding part, an overturning part, a vibrating part, a drying groove, a feeding groove, a containing box, an inclined plate, an opening and closing part and a driving part, and the sliding part is horizontally and slidably connected into the drying box; the overturning piece is arranged at the top of the sliding piece; the vibrating piece is connected to the top of the overturning piece; the drying groove is fixedly connected to the top of the vibration piece, and the end, close to the outlet, of the drying groove can extend out of the outlet along with movement of the sliding piece. The feeding groove is formed in the top of the drying box, and the opening and closing piece drives the inclined plate to rotate so that a discharging gap can be formed between the inclined plate and the discharging opening. The driving piece drives the containing box to move above the drying groove and enables the sodium thiocyanate to be dried in the drying groove to be evenly scattered in the drying groove through the discharging gap, the structure is simple, use is convenient, and the drying effect of the sodium thiocyanate is effectively improved.

This application relates to a flotation separation method for refractory mixed lead-zinc ores. The method includes: lead-preferential flotation, lead-zinc mixed flotation, lead-zinc separate flotation, and zinc flotation. During the lead-zinc separate flotation, a novel sphalerite depressant composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride, and sodium carbonate is added. Using the scheme provided in this application, lead and zinc concentrates can be produced separately, achieving efficient recovery of dense disseminated and fine-veined, complex, and refractory mixed lead-zinc ores, and has broad prospects for industrial application.

The utility model discloses a kind of sodium thiocyanate solid-liquid separation equipment, including processing box, the top of processing box is passed through and is fixedly connected with its feed hopper, the inner wall of processing box is fixedly connected with separation frame, the bottom of feed hopper is fixedly communicated with the top of separation frame, the bottom of separation frame is passed through and is equipped with through opening, the inner wall of through opening is fixedly connected with screening net, the right side of separation frame is passed through and is equipped with discharge port. The utility model integrates solid-liquid filtration separation and solid drying function in the same main frame, without additional setting material transfer device or step-by-step operation process; through the collaborative design of hot air conveying and rotary stirring, hot air can be uniformly conveyed to the solid material area through the hollow structure, and the stirring assembly continuously turns the material during rotation, so that the hot air and the material are in full contact, effectively solving the problem of uneven local drying that easily occurs in traditional fixed drying structure.

The invention relates to the technical field of pesticide synthesis, and discloses a continuous synthesis method of thiophanate-methyl. The method comprises the following steps: preparing dry sodium thiocyanate into an aqueous solution, and continuously reacting with methyl chloroformate and a catalyst in a microreactor; and carrying out condensation reaction on the obtained intermediate and o-phenylenediamine dissolved in the composite solvent in series connection stirring kettles, and carrying out programmed cooling and crystal growing, separation, washing and drying to obtain the product. According to the method, side reaction is effectively inhibited, the product purity is high, the quality is stable, the production efficiency and the reaction yield are remarkably improved, and the microreactor and the reaction kettle are connected in series to realize whole-process continuous operation; by using the self-made efficient catalyst, the dosage of the catalyst is reduced, the reaction condition is mild, the reaction temperature is effectively reduced, the process time is shortened, meanwhile, the catalyst has no peculiar smell, the problem of irritating odor is avoided, and the operation environment is friendly.

The application provides a combination catalyst and application thereof, and belongs to the technical field of fine chemical industry.The combination catalyst is composed of a phase transfer catalyst, an antioxidant and a buffer agent; the phase transfer catalyst is a crown ether phase transfer catalyst; the antioxidant is one or more of dilauryl thiodipropionate, dioctadecyl thiodipropionate, triphenyl phosphite and pentaerythritol diphosphite; and the buffer agent is one or more of potassium carbonate, sodium hydroxide and sodium bicarbonate.The combination catalyst has high activity, and when used in the reaction of synthesizing sodium thiocyanate and chloropropyl triethoxysilane, the combination catalyst has mild conditions, small dosage, easy control, simple operation, short reaction time, high yield, few by-products, reduced production cost, and improved product yield and quality.

The utility model discloses a reaction device for wet synthesis of sodium cyanate, which comprises a dissolving kettle and a synthesis kettle, and the dissolving kettle is communicated with the synthesis kettle through a pipeline; the dissolving kettle and the synthesis kettle are communicated with the o-dichlorobenzene tank through pipelines, the synthesis kettle is communicated with the filter through a pipeline, and the filter is communicated with the mother liquor tank through a pipeline. According to the wet synthesis device disclosed by the utility model, the dissolving kettle and the synthesis kettle are matched with the material transfer pump to finish feeding, dissolving, stirring and reaction of raw materials, the condensation reflux of a solvent is finished through the plurality of groups of condensers, and the spraying and recycling of tail gas are finished through the plurality of groups of spraying towers matched with the material transfer pump, so that the content of sodium cyanate produced by the whole wet synthesis device is higher; meanwhile, the generated ammonia gas can be converted into ammonium carbonate to be recycled, so that the production cost and the environmental pollution are effectively reduced.

The invention discloses a method for synthesizing paratoluensulfonyl isocyanate by a sodium cyanate method. The method comprises the following steps: S1, performing anhydrous treatment on raw materials including sodium cyanate, paratoluensulfonyl chloride and a solvent; s2, adding a certain amount of sodium cyanate, paratoluensulfonyl chloride, a phase transfer catalyst and a solvent into the reaction kettle, and stirring and reacting at 25-30 DEG C for 2-3 hours; s3, filtering out solids from a reaction product in S2, and extracting an organic phase; and S4, distilling the organic phase in S3 to recover the solvent, and performing reduced pressure distillation to obtain p-toluenesulfonyl isocyanate. According to the method for synthesizing the p-toluenesulfonyl isocyanate by the sodium cyanate method, provided by the invention, a high-yield and high-purity product can be obtained by optimizing reaction conditions and purifying steps.

The invention relates to an accelerator for mineral binder compositions, comprising a) an aqueous suspension of calcium hydroxide, and b) at least one material I selected from the group consisting of alkanolamines, sodium thiocyanate, sodium nitrate, sodium nitrite, calcium nitrate, calcium silicate hydrate, sodium silicate, aluminum sulfate, sodium sulfate, sodium aluminate, alkali metal carbonates, in particular lithium carbonate, alkali metal bicarbonate, especially sodium bicarbonate, an organic acid or a mixture thereof. The invention also relates to a method for accelerating a mineral binder composition with such an accelerator.