1665 results about "Dilute acid" patented technology

The invention relates to a pretreatment method of wood fiber raw materials, which belongs to the technical field of biomass chemical engineering. The process comprises the following steps: carrying out the first-step treatment after the wood fiber raw materials are mixed with mixed liquid of an organic acid solution and catalysts to obtain a liquid-solid mixture; separating the obtained liquid-solid mixture to obtain pretreatment black liquid and cellulose solids; washing the obtained cellulose solids by the organic acid solution to obtain washing black liquid and cellulose solids; adopting diluted acid or alkali for carrying out the second-step treatment on the obtained cellulose solids; mixing the obtained pretreatment black liquid and the obtained black liquid to obtain mixed black liquid; circularly using the mixed black liquid in the first-step treatment process; and recovering organic acids, lignin products and syrup solutions from the black liquid in the cyclic use for at least three times. The invention has the advantages that the full-rate development of raw materials can be realized, in addition, the environment-friendly effect can be realized, and the invention conforms to the requirement of modern biorefinery development.

The invention discloses a method for preparing a liquid seaweed fertilizer. The seaweeds serve as raw materials, and the method sequentially comprises the following steps: pulping and crushing fresh seaweeds or soaking and swelling dried seaweeds for pulping and crushing, performing ultrasonic extraction, performing solid-liquid separation, performing alkaline extraction on solid seaweeds, compounding the seaweed extraction solution and common fertilizers, thereby obtaining the liquid seaweed fertilizer. According to the method disclosed by the invention, the extraction efficiency of active ingredients in the seaweeds can be obviously improved, and compared with a traditional chemical extraction method, the method disclosed by the invention has the advantages that because a mild method is adopted, for example, ultrasonic extraction and relatively low temperature and dilute acid/dilute alkali assisted ultrasonic extraction are adopted, and the alkali extraction time is obviously shortened. According to the process technology, the activity of the active ingredient can be obviously preserved in the extraction process, so that high-activity seaweed extract and products thereof are obtained.

The invention relates to a dissolvent for cellulose dissolution through freezing-unfreezing method or direct dissolution method, and process for preparing the regenerated cellulose fibers and films by utilizing the dissolvent, wherein the dissolvent is the water solution of lithium hydroxide and urea whose compositions are 3.0-7.0wt% of lithium hydroxide, 4.0-30.0.0wt% of urea, the rest is water. The water solution of lithium hydroxide and urea can directly dissolve cellulose through freezing-unfreezing method or by pre-cooling the dissolvent in advance to -10 deg. C - -4 deg. C. It can be used to obtain high dissolvability transparent concentrated cellulose solution. By using the concentrated cellulose solution and through 3-5wt% diluted acid water solution coagulation, regeneration, regenerated cellulose films and fibers can be prepared.

The invention discloses a method for efficiently recovering active materials of positive poles in waste lithium batteries, which is mainly characterized by adding crushed electrical core fragments into hot water, stirring the mixture, and performing first vibration screening after the filtration and drying to separate most of an active material; dissolving aluminum foil through alkaline leaching after an oversize part is magnetically separated, adjusting the pH value of an alkaline leaching filtrate by dilute acid and ammonium bicarbonate solution, and recovering aluminum; performing second vibration screening after the filtration and drying to separate a residual powder material; and placing the oversize part into water for water cyclone separation, dumping to remove an upper-layer plastic diaphragm, then using dilute sulfuric acid and sodium thiosulfate solution to wash a copper sheet to ensure that carbon powder and active powder which are adhered to the copper sheet are loosened and fall off, making the powder float on an upper layer through cyclone separation after the washing, mixing the powder and the active powders obtained by two screenings, using NaOH solution to soak the mixture after the magnetic separation, calcining the alkali-leached active powder material after the filtration and drying, and taking the active powder material as active powder for subsequent treatment. The use of the method can ensure that the recovery rates of copper and aluminum in waste lithium ion batteries reach 98.5 percent and 97 percent respectively, and the recovery rate of the active materials is about 99 percent.

The invention relates to a method for copper powder surface chemical plating silver, belonging to field of chemical silver plating. Said method comprises following steps: putting copper powder into diluted acid of 5-10% to remove oxide on surface of copper powder; adding disperser of 1-30% of copper powder by weight, stabilizer of 10-60% of copper powder by weight into deionized water to form reducing liquid, adding copper powder and stirring; adding silver nitrate into deionized water, adding ammonia, stirring and adding sodium-hydroxide and getting silver amine solvent; adding silver amine solvent into reducing liquid under stirring, finishing chemical silver plating of copper surface 10-50 minutes later; filtering, separating and washing, vacuum drying and getting silver-coated copper powder. The process is characterized by simple preparation and raw material, reduced silver-plated layer on container wall by adding silver amine solvent into reducing liquid, high silver converting rate. The electrical resistance of got copper powder is smaller than 2*10-4 omegacm.

The invention discloses a preparation method of biomass-based nitrogenous porous carbon, the porous carbon prepared by the method and the use of the prepared nitrogenous porous carbon in a super capacitor. The preparation method comprises the steps of (1) drying a biomass material, and grinding the biomass material into fine powders, (2) evenly mixing the biomass material powders and water or a dilute acid solution, (3) placing the above mixture into a reactor for hydrothermal reaction, and (4) drying and grinding an obtained hydrothermal reaction product, and calcining the hydrothermal reaction product in a tube furnace to obtain a nitrogen-doped porous carbon material with a large surface area. According to the method of the invention, cheap and renewable plant is used as carbon and nitrogen precursors, and the porous nitrogen-doped carbon material is prepared through a hydrothermal method. The method has the advantages of simple preparation process, no need of an activator or template agent, low cost, environmental protection, and convenient operation, problems of strong corrosion, a high price of transition metal and environmental pollution caused by heavy metal are avoided, and the method is suitable for mass production.

The invention relates to a method for preparing a collagen peptide by taking a cod skin as a material; in the method, the cod skin is selected as the material and is washed clearly by fresh water; 0.2 percent-0.5 percent mixed liquid of calcium hyduloxide and sodium hydroxide is added for dipping; then the cod skin is washed by fresh water until the pH value is neutral; after the water liquid of 0.3 percent to 0.6 percent diluted acid is added for dipping, the cod skin is washed by fresh water again until the pH value is neutral; the cod skin is cracked and is stirred and extracted in hot water for extracting a collagen; then undissolved substances are removed through filtering; the pH value of the extraction liquid of the collagen is adjusted to be neutral; under the stirring conditions, enzymes are added for carrying out zymohydrolysis and obtaining a zymohydrolysis liquid; and after the enzymes are eliminated and filtering is carried out, the powder of the collagen peptide is obtained through vacuum condensing and sponging drying. The method has the advantages of simple technique, less device investment, no environment pollution and being suitable for industrialization production. The collagen content of the powder of the prepared collagen peptide is higher; and the color, smell and biological properties are excellent. The powder of the collagen peptide can be broadly applied to the industries of health-care foods, medicines, and the like.

The invention discloses a method for purifying smelting waste acid. The method comprises the following steps: adding a coordination agent into a centralized inflow adjusting pool of waste acid discharged from a sulfuric acid smelting system, stirring uniformly, and filtering the mixture in a filter to further remove insoluble granular impurities; separating dilute acid nearly containing no metal ion and low-acid wastewater through a diffusion dialyzer; adsorbing such residual anion impurities as fluorine and chlorine in the dilute acid through ion exchange resin, concentrating the dilute acid in a multi-effect evaporator and recycling the dilute acid in the sulfuric acid system; further treating the low-acid wastewater to reach the national sewage drainage standard. The method disclosed by the invention can be used for quickly and efficiently separating acid from heavy metal ions in the smelting waste acid, the separated dilute acid can be recycled in a sulfuric acid production procedure after being concentrated, and the method has the advantages of low energy consumption and few residues, and can be used for effectively and comprehensively recycling resources in the waste acid. The wastewater treatment cost is low, and the economic benefit is good. The process is simple, the occupation area of equipment is small and industrialized application is easy to achieve.

The invention relates to a preparation method for a high-concentration graphene-polyaniline nanofiber composite dispersion liquid and a high-concentration graphene-polyaniline nanofiber composite film. The method comprises: respectively adding graphite oxide and polyaniline nanofiber to two parts of distilled water to carry out ultrasonic dispersion to obtain a graphene oxide dispersion liquid and a polyaniline nanofiber dispersion liquid; adding the polyaniline nanofiber dispersion liquid to the graphene oxide dispersion liquid in a dropwise manner, then carrying out ultrasonic dispersion toform a composite dispersion liquid; mixing the composite dispersion liquid and a reducing agent, then carrying out the reaction under conditions of a constant temperature and ultrasonic wave to obtain the graphene-polyaniline nanofiber composite dispersion liquid; carrying out vacuum filtration for the graphene-polyaniline nanofiber composite dispersion liquid to prepare the composite film; adopting dilute acid leaching to prepare the self-supporting composite film with high conductivity. According to the method, the polyaniline nanofiber is adopted as the dispersion stabilizer for the graphene to prepare the high-concentration composite dispersion liquid, such that the problem of difficult removal of the traditional dispersing agent is solved, the synergistic effect of the composite material is easily provided. In addition, the prepared self-supporting composite film has good flexibility and high conductivity.

The invention provides an improved production process of utilizing gypsum to produce sulfuric acid and cement, which relates to the sulfuric acid and cement industry production technology, and the resource comprehensive utilization and environmental protection governing field of the industrial byproduct gypsum. The improved production process is characterized in that natural gypsum with the CaSO4*2H2O as the main composition or the industrial byproduct gypsum is adopted as the main source material; clay, coke and fly ash clinker are used as supplementary materials; the half-water drying gypsum flow, the single stage powder grinding, raw material mixing melting, suspension preheater kiln decomposing calcination, closing diluted acid washing and purification, two-turning and two-suction processes are adopted; the sulfuric acid and cement products are prepared through six steps of source material homogenizing, drying and dehydration, raw material preparation, clinker burning, kiln gas acid production and cement grinding; the improved production process has the advantages of wide range source material, solving the land occupation and environmental pollution problems of the gypsum waste residue, realizing the circulation utilization of sulfur resource, adopting a plurality of new processes and devices, realizing the large scale production easily, advanced technology, mature process, easy operation in production control, low energy consumption, high benefit, no waste water and waste residues exhaust.

The invention provides a method for preparing a porous graphene material. The method comprises the following steps of: (1) dispersing nano granules of a metal oxide into a solvent; (2) adding a soluble salt of a graphitization catalyst and a polymer into the product obtained in the step (1), and performing uniform mixing; (3) heating and vacuumizing the product obtained in the step (2) to remove the solvent; (4) thermally treating the product obtained in the step (3) for 0.5 to 400 minutes in inert atmosphere at the temperature of between 500 and 1,000 DEG C, and collecting a solid product after cooling; and (5) treating the solid product by using dilute acid to dissolve and remove the catalyst and the nano granules of the metal oxide so as to obtain the porous graphene material. The porous graphene material prepared by using the method has low oxygen content and high graphitization degree, and holes with diameter of more than 2 nanometers are distributed on the graphene sheet layer. The preparation method is simple, the raw materials are easily obtained, and the preparation method can be used for batch preparation and is easy to realize industrialized production.

The invention relates to a method for treating and reusing waste gas containing nitrogen oxide generated in industrial process. It comprises following steps: mixing waste gas containing nitrogen oxide with air according to a certain proportion, plural serial adsorbing it in tower by introducing it from bottom of head tower, discharging it from top of tail tower, discharging generated hydrogene nitrate of low concentration from bottom of head tower, proceeding decompressing and thickening process in thickening tower, which includes bleaching and dewatering; hydrogen nitrate of low concentration is introduced from top of thickening tower, hydrogen nitrate of high concentration being 45-65% is discharged from bottom; supercharging nitrogen oxide extracted from thickening tower top with vacuum system, then introducing it into adsorbing process again; the water or diluted acid from thickening tower is used as adsorbent and is added from top of tail tower in adsorbing process and counter current contacts with gas in tower for mass transferring. The waste gas treatment effect is good, and the discharging concentration of nitrogen oxide in exhaust gas is less than 50 ppm; all the nitrogen oxide in exhaust gas is recycled to generate aqua fortis with mass concentration being more than 55%.

The invention provides superparamagnetic nano Fe3O4 particles synthesized through in-situ induction of chitosan hydrogels, relating to a method for synthesizing the superparamagnetic nano Fe3O4 particles. The invention solves the problems of serious aggregation of the nano Fe3O4 particles and the complicated method for inducing the chitosan into the surface of the Fe3O4 in the current nano Fe3O4 particles. The method of the invention is that: 1. the chitosan powder is added into dilute acid solution; 2. cross-linking agent is added to make the chitosan hydrogels; 3. the chitosan hydrogels are sequentially dipped in Fe3+ aqueous solution, water, Fe2+ aqueous solution and water, and a plurality of times of circular leaching are made so as to form the chitosan hydrogels that contains iron ions; 4. then basification treatment is carried out; 5. the hydrogels is dissolved or degraded again, and finally the black superparamagnetic Fe3O4 nano particles are obtained upon centrifugalization. The method of the invention requires simple technique and mild conditions and the equipment used in the method is simple and can be obtained easily, thereby mass production can be achieved. The average diameter of the particles is 15 to 25nm, and the particles distribute evenly with superparamagnetism.

The invention discloses a transfer method of graphite film, which belongs to the field of material processing. The method aims at graphite prepared on nickel and other metal films by chemical vapor deposition method (CVD), and employs hydrogen bubble generated by reaction of a dilute acid solution and a metal substrate to separate the graphite layer and the metal substrate. PMMA and other polymers are not needed to cover the upper layer of the graphite for transferring carrier according to the invention, so no pollutants are introduced, and damage of graphite surface is greatly reduced; the peeling process is carried out by a direct chemical reaction between the acidic solution and the metal, thereby realizing separation of graphite on the upper and lower surface of the metal film and the metal film simultaneously with high efficiency and without external power source and electrochemical reaction. The invention has a simple operation technology and does not relate to harmful chemical substances. The metal substrate can be used for multitime with repetition, and the cost is greatly reduced. The invention has a large application value in the industrial field for large scale preparation of graphite.

The invention relates to a new method for processing lignocellulose by saccharification, comprising dilute acid pretreatment, milling and crushing, cellulase compounding and enzymolysis saccharification process. The detail method thereof comprises the following steps: the crushed lignocellulose raw materials are pretreated with dilute acid with the H <+> concentration of 0.01mol/L-0.1mol/L and later milled and crushed, and then acidolysis sugar solution is obtained; at least two types of cellulase are mixed with xylanase for obtaining compound cellulase, and then further enzymolysis saccharification treatment is carried out to the rest solid after enzymolysis and milling for obtaining enzymolysis sugar solution. By using the process that the milling of dilute acid is combined with the one-step enzymolysis of compound enzyme, the hydrolysis sugar yield of the lignocellulose raw materials can be up to more than 90 percent. The method has the advantages of mild reaction condition, simple operation, and high enzymolysis efficiency; moreover, the obtained sugar solution after being processed produces no inhibition to the follow-up fermentation, can be comprehensively utilized, and causes no environmental pollution, etc.

The invention discloses a method for preparing hollow high voltage nickel manganese acid lithium anode material, and belongs to the technical field of material synthesis. The method includes the steps that firstly, manganese carbonate is prepared and then calcined under a certain temperature to make the outer shell of the manganese carbonate become manganese dioxide, then, the inner core of the manganese carbonate is dissolved away with dilute acid, the manganese dioxide outer shell is left and mixed with a lithium source and a nickel source, and the hollow nickel manganese acid lithium material is obtained in a calcined mode. The nickel manganese acid lithium material prepared with the method is of a uniform micrometer/nanometer structure and is 1-5um secondary particulates formed by 30-400nm particulates, and primary particulates in small sizes shorten the transmission distance of lithium ions, increase the area of contact between electrodes and electrolytes, and improve the rate capacity. The nickel manganese acid lithium material particulates prepared with the method are of a hollow structure, gaps can buffer structural stress and size changes caused by ithiation, and circulating performance is improved.

The present invention belongs to the field of nanometer material technology. The procedure is: 1) adding 1-30 parts of TiCl4 or TiO2 powder to 70-99 parts of organic solvent, obtaining evenly distributed mixture, 2) dissolving 10-60 parts of potassium hydroxide in 40-90 parts of deionization water, obtaining NaOH solution, 3) adding 20-80 parts NaOH solution of step 2)to 10-50 parts solution of step 1), stirring and moving to an autoclave, thermostatically heating at 50-300 degree C, 4) cooling down and pouring out the supernatant liquid, washing the bottom precipitation with deionization water and diluted acid solution, followed by centrifugal separating and drying at 10-200 degree C. The product obtained is one dimension single crystal nanometer material (nano-wire, nano-rod, and nano-tube) of TiO2 with diameter of 10-100 nm and length of micrometer order of magnitude. The product of the present invention is of high purity and high yield rate, and the form and pattern can be adjusted through selecting different solvents.

The invention relates to a manufacturing method for tempering cellulose fiber with intelligent tempering performance, characterized in that microcapsule grout of phase change energy storage materials with the weight of 10-230% of the fiber is put into the fiber stock solution of cellulose so as to form spinning dope by even mixture, which enters into the dilute caustic soda solution and dilute sulfate in turn to form the fiber; tempering cellulose fiber is formed by dilute acid decoppering, washing and drying. It is provided with simple process, low manufacturing cost and wide applicable range. The tempering cellulose fiber has the base material of cellulose fiber and the functional additive material of microcapsule of phase changer energy storage materials. The phase change energy storage materials are not easy to leak and is provided with good heat stability and tempering effect. When it is applied in down-proof fabric and duvay the phase change energy storage materials can strengthen the tempering performance.

The invention discloses a method for recovering valuable metal from waste and old nickel cobalt lithium manganate ternary battery positive materials. The method comprises the steps that (1) the nickelcobalt lithium manganate ternary battery positive materials subjected to disassembling and grinding are uniformly mixed with carbon powder; then, roasting reduction is performed; the temperature is controlled to be 700 to 950 DEG C, and the time is 1.5 to 4h; (2) roasting materials are put into a stirring device; pure water is added; dilute acid is dropwise added; the PH is regulated to be 4.5 to8; after the soaking, filtering treatment is performed; (3) filtering liquid obtained after filtering is taken; the filtering liquid is regulated by sodium hydroxide until the PH is 7.0 to 10.0; after filtering for impurity removal, soluble carbonate is added; lithium carbonate is precipitated; the lithium carbonate is precipitated, filtered and washed; the recovery of lithium metal elements is realized. An positive powder reduction mode is used; firstly, lithium is converted into dilute acid or water soluble substances; no impurities exist; high-grade lithium is preferably recovered; then, the cobalt, nickel and manganese ternary materials are recovered and utilized in a unified way; the process is simple; the environment is protected; the efficiency is high; wide industrial applicationprospects are realized.