2500 results about "Organic acid" patented technology

The invention belongs to the technical field of oil and gas development, and particularly relates to an oil and gas well blocking remover and a preparation method thereof. The blocking remover comprises the following components: 5-8% of low-carbon composite organic acid, 5-7% of fluoboric acid, 6-9% of ammonium bifluoride, 4-6% of an anti-acid sludge mutual solvent, 2-4% of a corrosion inhibitor, 2-4% of polyoxypropylene polyoxyethylene propylene glycol ether, 8-12% of a permeation dispersion surfactant, 2-5% of a sulfur dissolving agent, 2-5% of a stable chlorine dioxide solution and the balance of water. The preparation method comprises the following steps: adding the low-carbon composite organic acid, the fluoboric acid and the ammonium bifluoride into water and stirring; adding an acid sludge resisting mutual solvent and a sulfur dissolving agent, and stirring; adding the corrosion inhibitor, the polyoxypropylene polyoxyethylene propylene glycol ether and the permeation dispersion surfactant, and stirring; and finally, reducing the stirring speed, adding the stable chlorine dioxide solution, and stirring to uniformly mix. The blocking remover provided by the invention is comprehensive in blocking removal function, very good in dissolving and dispersing performance on complex blocking substances, very small in corrosion damage to a shaft pipe wall and wide in applicability.

The invention relates to the technical field of retired ternary power battery recovery, and particularly discloses a method for preferentially extracting lithium and recovering valuable metals from a retired ternary lithium battery and application of the method. According to the method, the traditional process is broken through the preferential lithium extraction, and efficient recovery of lithium, Ni, Co and Mn is realized by utilizing'fast-medium-slow 'multi-stage cooperation of a composite reducing agent and accurate adaptation of roasting and leaching parameters, so that the method has the advantages of low cost, high efficiency, low energy consumption and the like, and is suitable for large-scale industrial production. The method is low in energy consumption and environment-friendly, and is applied to resource recycling of the retired ternary lithium battery, and the precursor can be used for reproducing a positive electrode material or used for a catalytic material.

The invention relates to a composite reverse osmosis membrane acidic cleaning agent, a preparation method and a cleaning process thereof, and belongs to the technical field of environment-friendly water treatment. The cleaning agent comprises the following components in percentage by mass: 4-8% of inorganic acid, 20-40% of organic acid, 1-3% of a surfactant, 0.5-1% of a chelating agent, 0.5-1% of a compound corrosion inhibitor and the balance of deionized water. The composite corrosion inhibitor is formed by compounding 2-mercaptobenzothiazole and the like according to a specific mass ratio, the molecular weight of polyaspartic acid is 5000, and the molar ratio of Zn to Mo in the zinc-molybdate compound is 2: 1. The preparation method comprises the following four steps: firstly preparing a compound corrosion inhibitor premix, then preparing an acidic base solution, and then sequentially adding the components to finally obtain the cleaning solution. According to the cleaning process, a cleaning agent and deionized water are mixed, the membrane flux recovery rate is larger than or equal to 85% through cleaning of a specific process, the reverse osmosis membrane can be effectively cleaned, and the performance of the reverse osmosis membrane can be recovered.

The invention provides a carbon emission management monitoring method and device for rice planting in a cold region, and relates to the technical field of carbon emission management monitoring. Vertical three-layer parameters of a soil profile, namely the surface methane concentration, the middle oxidation-reduction potential and the deep organic acid concentration, are collected; the method comprises the following steps: mapping a middle-layer potential into an inhibition coefficient according to a microbial electrochemical principle, further calculating potential uplink electron flux and actual downlink electron sedimentation intensity, identifying an electron transport chain breakage risk through a residual error of the potential uplink electron flux and the actual downlink electron sedimentation intensity, and carrying out nonlinear fusion on the electron transport residual error and environment weights of all layers by adopting a p-norm model. Through the risk amplification coefficient, the superlinear conduction of the local risk to the whole system is realized, the dominant risk layer is accurately positioned based on the comprehensive weight, the differential field management strategy is automatically generated, and finally the closed-loop intelligent management normal form is constructed, and the accurate control of the carbon emission based on the mechanism model is realized.

The invention relates to the technical field of welding materials, and discloses washable semiconductor solder paste and a preparation method and application thereof. The washable semiconductor solder paste comprises scaling powder and tin powder, wherein the mass ratio of the scaling powder to the tin powder is 1: (8-9.6); the soldering flux comprises the following raw material components: a film-forming agent, composite organic acid, a thixotropic agent, a surfactant, an antioxidant and a solvent, wherein the composite organic acid is composed of succinic acid and glutaric acid according to the mass ratio of (1-3): (1-2.5). According to the washable semiconductor solder paste, the particle size, the melting point and the alloy components of the tin powder are controlled, composite organic acid composed of succinic acid and glutaric acid in a specific proportion is adopted in the soldering flux, and other components are matched with one another; the tin powder and the soldering flux in a specific mass ratio are combined, so that the prepared washable semiconductor solder paste is good in wettability, the expansion rate is larger than or equal to 85%, the storage life reaches 3 months, and the washable semiconductor solder paste can be directly cleaned with water after being welded and is high in corrosion resistance and oxidation resistance.

The invention discloses a method for preparing 12-mercaptan through solid organic acid catalysis, belongs to the technical field of 12-mercaptan preparation, and aims to solve the problems of low catalyst activity, harsh reaction conditions, serious pollution, high cost and dependence on import in the prior art. N-dodecanol and hydrogen sulfide are used as raw materials and are mixed according to the molar ratio of 1: 1.2-1: 1.3; the method comprises the following steps: gasifying n-dodecanol, mixing with purified hydrogen sulfide, preheating to 210-240 DEG C, introducing into a fixed bed reactor filled with a solid organic acid catalyst, and reacting at-0.08-3.0 MPa for 3.5-4 hours; and cooling and condensing the reaction product, carrying out gas-liquid separation, rectifying and purifying the liquid product to obtain 12-mercaptan with the purity of more than or equal to 99.5%, and recycling unreacted hydrogen sulfide. The solid organic acid can be a catalyst of p-toluenesulfonic acid and the like or mesoporous silica loaded nickel, cobalt and molybdenum metal oxides. The method has the advantages of high catalytic activity, mild reaction conditions, high product yield (the conversion rate of n-dodecanol is greater than or equal to 94.5%), environmental protection and low cost, can realize the domestic mass production of 12-mercaptan, and meets the market demand.

The invention discloses a preparation method and application of organic peptide salt in the field of organic peptide salt, and the preparation method comprises the following steps: step 1) extraction of azolla filliculoidas active peptide: performing crushing, enzymolysis or ultrasonic-assisted extraction on azolla filliculoidas raw materials to obtain an azolla filliculoidas active peptide crude extract; and (2) purifying the rumex hanus active peptide. According to the method, the azolla filliculoidas active peptide is subjected to graded purification by adopting an ultrafiltration membrane separation technology, an active peptide component with uniform molecular weight distribution is obtained, and a high-quality raw material is provided for subsequent reaction; organic acid selection and reaction conditions are optimized, the yield and purity of the organic peptide salt are remarkably improved by selecting specific organic acid and optimizing the reaction conditions, ultrasonic-assisted reaction is introduced, the uniformity and efficiency of the reaction are improved through the ultrasonic-assisted reaction, and the stability and functionality of the organic peptide salt are further enhanced. The prepared organic peptide salt is not only suitable for the field of food, but also can be widely applied to health care products and cosmetics, and has remarkable market potential.

The invention discloses stable silicon dioxide microspheres as well as a preparation method and application thereof. Mixing a sodium silicate diluent and an organic acid aqueous solution to form colloidal particles, and carrying out a sol-gel reaction to obtain silica sol; the preparation method comprises the following steps: in an air environment, throwing silica sol into water under stirring to form microspheres, injecting inorganic acid into the water at the same time, then injecting a sodium silicate diluent for reaction, and then adjusting the pH value of the system to 6-7; and aging, washing, drying and roasting to obtain the silicon dioxide microspheres. The preparation method comprises the following steps: mixing a sodium silicate diluent and an organic acid aqueous solution by an acid mixing method, granulating by air to form microspheres, and finally injecting inorganic acid to quickly remove heat, reduce pressure drop and maintain the state of the microspheres, thereby obtaining the stable silicon dioxide microspheres. The porous silicon dioxide microsphere with larger surface area and pore volume is obtained, has better catalytic performance when being used as a catalytic oxidation carrier, and has the advantages of high conversion rate and high stability.

The invention relates to a method for efficiently extracting lithium by roasting lepidolite at low temperature by using composite organic acid. The invention relates to a method for efficiently extracting lithium by roasting lepidolite at low temperature by using composite organic acid, which comprises the following steps of: adding an activating agent into lepidolite concentrate, and pre-activating to obtain activated lepidolite concentrate powder; the lepidolite concentrate powder and a composite organic acid roasting agent are mixed, acidified and roasted, and a roasted product is obtained; adding water into the roasted product for leaching, and carrying out suction filtration to obtain a lithium-containing leachate; the composite organic acid roasting agent at least comprises methanesulfonic acid. According to the method, the problem that the lithium ion extraction efficiency is low due to the fact that the TOT layered structure in the lepidolite is difficult to damage is solved, and the problem that the lithium ion extraction efficiency is low due to the fact that Si-O bonds with high bond energy in an existing lepidolite crystal framework are difficult to dissociate is also solved.

A composition having an additive or component having an antimicrobial or a preservative property, and 3-phenylpropanol or a member of the phenylpropanoid family is provided. A composition having a polymer, an organic acid, and 3-phenylpropanol or a member of the phenylpropanoid family is provided as well as a method(s) of using.

The invention belongs to the technical field of electrolyte materials, and particularly relates to a pH response biopolymer solid electrolyte as well as a preparation method and application thereof. The pH-responsive degradable biopolymer is taken as a main raw material, and one or more functional groups such as pyridine, sulfonic acid, carboxyl, tertiary amine, phosphoric acid and the like are contained. The organic acid and the organic acid salt are selected to adjust the pH value of a medium around the electrolyte, and the contraction / stretching behavior of a molecular chain is influenced by changing the ionization degree of the electrolyte, so that an interpenetrating polymer network structure is formed. The polar functional group of the biopolymer affects the migration behavior of lithium ions under different pH conditions, so that the migration rate and migration quantity of the lithium ions are increased, and the cycle performance of the battery is improved. The electrolyte is suitable for high-performance energy storage devices such as a lithium ion battery, can effectively improve the battery performance, reduces the environmental pollution, and has relatively strong green and environment-friendly advantages.

The invention belongs to the field of carbon nanomaterials, and relates to a cobalt molybdenum / magnesium aluminum metal catalyst, a preparation method and application thereof, and a preparation method of a carbon nanotube. The preparation method of the cobalt molybdenum / magnesium aluminum metal catalyst comprises the following steps: S1, carrying out chelation reaction on metal salt and small molecular organic acid in a solvent, adjusting the pH value of the obtained chelation product to 3-7.5, and mixing the chelation product with a modifier to form gel; and S2, roasting the gel to obtain the cobalt molybdenum / magnesium aluminum metal catalyst. The preparation method is characterized in that in the preparation process of the cobalt-molybdenum / magnesium-aluminum metal catalyst, small-molecular organic acid is used as a chelating agent, and a specific modifier is used as an accelerant and a stabilizer, so that the prepared cobalt-molybdenum / magnesium-aluminum metal oxide has good structural stability and catalytic performance, and when the cobalt-molybdenum / magnesium-aluminum metal oxide is used as a carbon nanotube synthesis catalyst, the catalytic performance of the catalyst is greatly improved. Not only can the carbon yield be improved, but also the few-walled carbon nanotube with small tube diameter and high length-diameter ratio can be obtained.

The invention discloses a pretreatment method for efficiently extracting calcium in shrimp and crab shells. The pretreatment method comprises the following steps: carrying out microwave treatment on the shrimp and crab shells until the weight is constant, rehydrating for 10 minutes in a water bath at 90 DEG C, carrying out microwave treatment until the weight is constant, crushing, mixing with an acetic acid solution, stirring, centrifuging, and measuring the calcium concentration. According to the method, through microwave-rehydration-secondary microwave pretreatment, the carapace structure is destroyed, the contact area of organic acid and calcium is increased, the calcium recovery rate is increased, the treatment time is shortened, the energy consumption is reduced, the universality of raw materials is enhanced, comprehensive utilization of resources is facilitated, and the method is environmentally friendly and economical.

The invention discloses heavy metal resistant bacillus velezensis as well as a microbial remediation agent and application thereof. Bacillus velezensis DBS01 is screened from heavy metal contaminated soil in Dabaoshan mining areas in Shaoguan City, Guangdong province, is preserved in China Center for Type Culture Collection (CCTCC), has a preservation number of CCTCC M 20252228, not only has resistance to various heavy metals, but also can metabolize and secrete metabolites such as organic acid, cellulase and growth hormone in different growth stages, and can be used for preventing and treating various heavy metals. Multiple functions of curing heavy metals, dissolving phosphorus and potassium, promoting plant growth and the like are realized. According to the method, bacillus velezensis DBS01 is inoculated into a culture medium containing straw, calcium superphosphate, agar and sodium alginate are added, and a mixture containing the bacillus velezensis DBS01 is freeze-dried, so that the heavy metal contaminated soil in the mining area can be efficiently repaired in an environment-friendly manner at low cost, and the ecological function recovery of the soil is effectively promoted.

A polishing liquid which reduces the occurrence of erosion and scratches on a surface to be polished of an object to be polished having a cobalt-containing film after polishing in a case where the polishing liquid is applied to CMP of the object to be polished is provided. In addition, a chemical mechanical polishing method using the above-mentioned polishing liquid is provided. The polishing liquid is a polishing liquid used for chemical mechanical polishing of an object to be polished having a cobalt-containing film. The polishing liquid includes colloidal silica, an organic acid, a specific nitrogen-containing aromatic heterocyclic compound and hydrogen peroxide, and has a pH of 8.5 to 12.

The invention relates to the technical field of microorganisms, in particular to a strain of Lactiplanilla pentosuses ZF634 and application of the strain of Lactiplanilla pentosuses ZF634 and the application of the strain of Lactiplanilla pentosuses ZF634. The lactobacillus pentosus strain ZF634 is obtained through screening and still has efficient acid production capacity in a bean-based culture medium, and the bean curd coagulator prepared from fermentation liquor of the lactobacillus pentosus strain ZF634 has the function of enhancing aroma and flavor; the beany flavor of the prepared sour slurry bean curd is obviously reduced, and the sour slurry bean curd also has special milk flavor; the protein hydrolysis degree and flavor precursor substance accumulation of the prepared fermented bean curd embryo are far superior to those of a commercial sour slurry water sample, the content of fresh and sweet amino acids and organic acids is remarkably increased, the fresh and sweet taste of the fermented bean curd is improved, the taste is softer and more harmonious, the sensory quality of the final product is broken through, and the aroma, the taste and the texture are remarkably improved.

The invention discloses a fermentation process of citric acid residues, and relates to the technical field of organic acid fermentation. The fermentation process comprises the following steps: mixing and crushing citric acid residues and wheat bran according to a mass ratio of (4-5): 1 to obtain a mixed material; spraying an ammonia water solution, a magnesium sulfate solution and a zinc sulfate solution into the mixed material, adjusting the pH value to 5.0-5.5, sterilizing, adding a urea solution and a basic nutrient solution, and uniformly mixing to obtain slurry; aspergillus niger and saccharomycopsis fibuligera are mixed according to the spore number ratio of 100: 1, then sterile water is added, the mixture is stirred to be uniform, and bacterial liquid with the spore concentration of 1 * 10 < 7 >-5 * 10 < 7 > / mL is obtained; spraying the bacterial liquid to the surface of the slurry, performing aerobic culture for 40-48 hours under the conditions that the temperature is 30-35 DEG C and the humidity is 80-85%, then cooling to 25-30 DEG C, reducing the humidity to 70-75%, spraying methanol at the same time, and performing sealed culture for 5-6 days; performing drying; and the acid yield and the nutrient substance yield in the finally obtained fermentation product are obviously improved.

Disclosed in the present disclosure is a method for selectively leaching scandium from red mud. The red mud contains scandium, and the method comprises: using an inorganic acid solution to pretreat red mud to obtain pretreated red mud slurry; and using a leaching agent to carry out selective leaching on the pretreated red mud slurry to obtain leached slurry, the leaching agent containing organic acid and metal inorganic salt, and the mass ratio of the organic acid to the metal inorganic salt being 0.00015-0.0500.

The present invention belongs to the fields of pyrolyzed carbon black reinforcement, and the manufacturing of tires and non-tire rubber products. Provided are an interfacial reinforcing agent for pyrolyzed carbon black, and reinforced pyrolyzed carbon black and the use thereof. The interfacial reinforcing agent for pyrolyzed carbon black comprises the following components in parts by mass: 0.1-10 parts of a main interfacial reinforcing agent and 0.1-3 parts of an auxiliary interfacial reinforcing agent, wherein the main interfacial reinforcing agent comprises one or more of a nitrogen-containing compound, an active-double-bond-containing compound and a sulfur-containing compound; and the auxiliary interfacial reinforcing agent comprises one or more of a coupling agent compound, an organic acid compound and an amide compound. With regard to different functional groups (including double bonds, oxygen-containing functional groups, etc.) contained in the surface of the pyrolyzed carbon black, a suitable interfacial reinforcing agent is selected for modification to make the interfacial reinforcing agent react with the surface of pyrolyzed carbon black, thereby improving the tensile strength of the modified pyrolyzed carbon black in a rubber system.

To provide a biomethane production method and a biomethane production apparatus by which an amount of biomethane to be obtained can be increased, and operation can be performed stably.SOLUTION: A biomethane production method includes a methane fermentation process of processing organic waste 1 containing hardly decomposable solid matters in a methane fermentation tank 11 where methane bacteria exist. In the methane fermentation process, when supplying at least one of organic acid 2 and biodegradable resin and hydrogen 3 into the methane fermentation tank 11, a ratio of a supply amount of the hydrogen 3 to a supply amount of the organic acid 2 and the biodegradable resin is set to 0.10 L / gCOD or more and 1.50 L / gCOD or less such that pH inside the methane fermentation tank 11 becomes 7.0 or more and 9.0 or less.SELECTED DRAWING: Figure 1

An object is to obtain an ink set capable of forming images of excellent image quality even when an acidic atmosphere, arising from use of a volatile acid in a pretreatment solution, is present in the vicinity of ink nozzles, etc. As a solution, an ink set containing a pretreatment solution and an ink composition is provided, wherein: the pretreatment solution contains an organic acid having a boiling point of 120° C. or lower at 1 atmospheric pressure; and the ink composition contains a pigment and an alkali-soluble resin having an acid value of 200 mgKOH / g or higher or crosslinked substance thereof accounting for 1.8% by mass or more in the ink composition, and further contains a water-dispersible resin and water.

The present invention relates to a preparation method for a silicon-carbon composite negative electrode material, comprising the following steps: (P1) co-polymerization: co-dissolving an unsaturated organic acid, an acrylate monomer and an acrylamide monomer in water at a specific ratio, and co-polymerizing same under the action of a sacrificial agent of a saturated organic acid and an initiator to obtain a suspension containing an acrylic copolymer; (P2) alkali treatment: performing an alkali treatment and filtration on the suspension to obtain copolymer particles; (P3) in-situ polymerization: performing in-situ polymerization of phenolic aldehyde on the surfaces of the copolymer particles to obtain a composite resin of a phenolic aldehyde-coated acrylic copolymer; (P4) heat treatment: performing a heat treatment on the composite resin in an oxidizing gas atmosphere to obtain porous carbon; and (P5) performing silicon deposition and carbon coating on the porous carbon to obtain the silicon-carbon composite negative electrode material. When the silicon-carbon composite negative electrode material prepared in the present invention is used in a lithium battery, the volume expansion of silicon can be effectively relieved, and the cycling performance and charge-discharge capacity of a lithium-ion battery are improved.

The application discloses a solid dispersion of tolvaptan, and the raw material composition of the solid dispersion comprises tolvaptan, a hydrophilic carrier material, a hydrogen carbonate, and can further comprise a plasticizer and / or an organic acid. The solid dispersion is prepared by a hot melt extrusion process, the solubility of tolvaptan raw material can be obviously increased, and the oral preparation prepared from the solid dispersion can meet the sink condition of dissolution detection, and the accuracy of the detection result is ensured.

Escherichia coli is modified by means of metabolic engineering, a genetically engineered bacterium for high yield of O-succinyl-L-homoserine is obtained, and a construction method of the genetically engineered bacterium comprises the following steps: weakening a synthetic route of an organic acid metabolic byproduct of a chassis strain E.coli W3110 [delta] metI [delta] metJ [delta] thrB [delta] metB; wherein the synthetic route of the organic acid metabolic byproducts is selected from at least one of a formic acid synthetic route, a lactic acid synthetic route and an ethanol synthetic route. The constructed genetically engineered bacterium is applied to microbial fermentation production of the O-succinyl-L-homoserine, effective accumulation of the O-succinyl-L-homoserine is achieved, the sugar acid conversion rate reaches 46.8%, and a foundation is laid for subsequent construction of high-yield O-succinyl-L-homoserine engineering bacteria.

The invention discloses a novel wet flue gas desulfurization composite synergistic additive and a preparation method thereof, and relates to the technical field of flue gas desulfurization. The novel wet flue gas desulfurization composite synergistic additive comprises the following raw materials in parts by weight: 15-25 parts of organic acid, 10-20 parts of organic salt, 5-10 parts of inorganic salt, 4-5 parts of a wetting agent, 5-8 parts of a moisture absorbent and 5-15 parts of an accelerant. The prepared novel wet flue gas desulfurization composite synergistic additive has good calcium carbonate dissolution rate and calcium sulfite oxidation rate, and the desulfurization efficiency is high.

The invention belongs to the technical field of chemical engineering and secondary resource utilization, and particularly discloses a collaborative utilization process of sodium sulfate and ammonium-containing waste salt. The high-value utilization method of sodium sulfate provided by the invention comprises the following steps: mixing sodium sulfate, organic ammonium salt and sulfuric acid, and adding water to prepare a mixed solution; extracting the mixed solution by using an extracting agent, and separating a water phase from an organic phase; adding a pH regulator into the water phase to regulate the pH to alkalescence, introducing carbon dioxide gas to fully react, cooling, crystallizing, and filtering to obtain filtrate and sodium bicarbonate precipitate; heating the filtrate for evaporative crystallization to obtain ammonium sulfate; and recovering the organic acid in the organic phase. The invention provides a subversive solution for sodium sulfate by-product accumulation and ammonium-containing wastewater treatment, has double values of resource circulation and carbon emission reduction, and has the advantages of full-flow closed-loop design, wide applicability, high product purity and high economical efficiency in process.

The disclosure relates to compositions and methods for altering the color of hair, the compositions comprising at least one organic acid and / or a salt thereof, and at least one solvent.

The invention provides a double-dosage-form copper acid etching solution as well as a preparation method and application thereof. The double-dosage-form copper acid etching solution comprises an agent A and an agent B, the agent A comprises the following components in parts by weight: 15-20 parts of an oxidizing agent, 4-7 parts of an organic acid chelating agent, 0.1-0.5 part of inorganic acid, 0.5-2 parts of alkali, 1-2 parts of a surfactant and 0.01-0.1 part of a metal corrosion inhibitor; the agent B is prepared from the following components in parts by weight: 25 to 30 parts of organic acid chelating agent, 0.2 to 0.5 part of inorganic acid, 15 to 20 parts of alkali, 1 to 2 parts of surfactant and 0.1 to 0.3 part of metal corrosion inhibitor. The double-agent copper acid etching solution provided by the invention can be compatible with etching of Cu / Mo and Cu / MTD film layers, can be compatible with etching of film layers with different thicknesses, and is long in service life, low in CD Bias, free of chamfer cracks, good in residue, small in taper variation and short in etching time.

This invention provides a method and application for the comprehensive utilization of chlor-alkali salt mud solid waste to prepare a composite de-icing agent, belonging to the field of comprehensive utilization of solid waste resources and composite material synthesis technology. The invention first prepares a slurry by mixing chlor-alkali salt mud with water. Then, under the action of an acidification aid and an ionic liquid, organic and inorganic acids are added in a single step, followed by precipitation of the composite de-icing agent in an alcohol precipitation solution. The method of this invention achieves a salt mud utilization rate of 86.55-88.85% and an effective component extraction rate of 96.70-99.27%, especially for Ca... 2+ Na + K + Mg 2+ Al 3+ The extraction rates reached 95-99.99%, 99.9%, 99.9%, 85.5-95.0%, and 80.5-90.0%, respectively, and also improved the extraction efficiency of Ca in the solution. 2+ Na + K + Mg 2+ Al 3+ The precipitation rates reached 95.5-99.5%, 75.5-80.5%, 72.5-75.5%, 95.5-99.5%, and 71.5-75.5%, respectively, and the product yield reached 90.80-95.08%. It has broad prospects for snow melting and ice removal in low-temperature environments of -15℃ to -20℃.

The invention discloses a composite flocculant for adsorbing, flocculating and settling Ca < 2 + > in a water body and a method for removing high-concentration Ca < 2 + > in wastewater, and belongs to the technical field of wastewater treatment.The composite flocculant comprises sodium carbonate, magnetic seeds and organic acid modified starch; the magnetic seeds and the organic acid modified starch in the composite flocculant can synergistically promote the formation of magnetic flocs under the stirring action, and the sedimentation rate is increased; the organic acid modified starch and Ca < 2 + > form a stable chelation structure through the coordination and complexation of internal hydroxyl groups and acid radicals, and finally Ca < 2 + > is removed; the organic acid modified starch can flocculate and adsorb calcium carbonate and magnetic seeds at the same time, and recycling and reusing of the magnetic seeds are facilitated while calcium carbonate is settled. The modified starch flocculant and the magnetic flocculation technology provided by the invention can well remove impurities in wastewater; especially for excessive calcium ions, the method not only can improve the removal rate, but also can reduce the flocculation cost, and is suitable for popularization in industrial wastewater treatment.