195 results about "CAUSTIC ALKALIS" patented technology

In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

The invention belongs to the technical field of ternary material precursor preparation, and particular to a method for preparing a ternary material precursor and recovering lithium by using spent lithium-ion battery ternary cathode materials. Spent lithium-ion battery anode materials are roasted and screened to obtain ternary anode materials and aluminum foil; the ternary anode materials are leached out of a caustic soda solution and filtered to obtain filtrate and filter residues; carbonate is added to the filtrate to react to obtain lithium carbonate solid; the filter residues are leached with volatile acid; a reducing agent is added to the leaching solution and the volatile acid is removed by heating the solution to a boil; the molar ratios of nickel, cobalt and manganese in leaching solution are adjusted; and the leaching solution after adjusting the molar ratios of the nickel, the cobalt and the manganese is flow into a reaction kettle containing an ammonia water solution togetherwith the ammonia water solution and caustic solution, and coprecipitation is performed under inert gas protection. The method for preparing the ternary material precursor and recovering the lithium by using the spent lithium-ion battery ternary cathode materials realizes the preparation of the ternary material precursor and the recovery of the lithium at the same time, the production cost is reduced, product quality is high, economy is good, and the directional circulation of nickel-cobalt-manganese lithium resources is realized.

The invention discloses a lead compound nano-powder preparation method for recovery and manufacture of lead-acid battery. The lead compound nano-powder preparation method comprises the following steps that 1, lead, a lead salt or waste lead-acid battery lead paste reacts with one or more organic or inorganic compounds to produce a soluble lead salt solution or a lead hydroxide solution; 2, one or more alkalis or caustic alkalis are added into the soluble lead salt solution, or a part or excess amount of H2CO3 or CO2, sulfuric acid, one or more organic acids or their salts are added into the lead hydroxide solution, and 3, lead oxide or lead hydroxide precipitates obtained by the step 2 are filtered and are subjected to drying and pyrolysis to form the lead compound nano-powder. The lead compound nano-powder preparation method realizes environmentally friendly recovery and production, has low energy consumption, greatly reduces a production cost, and shortens a production period. The lead compound nano-powder obtained by the lead compound nano-powder preparation method is conducive to improvement of technical product performances.

The invention relates to a synthesis method of hydroxamate. The hydroxamate is synthesized from fatty acid, short chain alcohol, dodecyl sulfonic acid, hydroxylamine hydrochloride and caustic alkali by two steps; and the synthesis method comprises the following steps of adding fatty acid, short chain alcohol and dodecyl sulfonic acid into a reactor, stirring and reacting at a constant temperature of 75 DEG C-100 DEG C; carrying out reduced pressure distillation on the reactants to obtain fatty acid ester; adding hydroxylamine hydrochloride into another reactor, adding caustic alkali in batches while stirring, and mixing; adding fatty acid ester and reacting for 3-5 hours at 40 DEG C-60 DEG C to obtain a hydroxamate solution; and rapidly cooling the hydroxamate solution to obtain the solid hydroxamate. By the synthesis method, the conversion between acid-alkali environment for the esterification and hydroximation two-step reaction is avoided, the synthesized product needs not to be subjected to processing steps such as acidification, impurity removal and purification and the obtained product can be organically combined with flotation industry. The synthesis method has the advantages that the operation is simple, the yield of the product is high, the generation of a large amount of acidic wastewater is avoided and the cost of chemical agents is effectively decreased.

The invention relates to a multifunctional bio-charcoal and a preparation method thereof. According to the technical scheme, the preparation method comprises the steps of dipping biomass into 1-15wt% caustic alkali solution for 1-50h, washing with water to be neutral, and drying to obtain treated biomass; then charring the treated biomass in a tube furnace in mixed gas at 300-900 DEG for 1-130h to obtain the multifunctional bio-charcoal. The biomass is one of rice straw, wheat straw, sawdust, wood, green grass, fruit peel and animal tissue waste; the biomass contains 30-60wt% of volatile organic carbon of charcoal, 10-40wt% of fixed carbon, 1-30wt% of ash and 10-60wt% of water. The preparation method disclosed by the invention has the characteristics of low production cost, high yield, simple process, controllable production process and environment friendliness, and the prepared multifunctional bio-charcoal has a good adsorption effect on heavy metals and high stability and can be used for repairing water bodies, solid matrixes and soil which are polluted by heavy metals.

The present invention relates to a non-catalytic process for reducing NO_x concentrations in the regenerator off-gas stream of a fluid catalytic cracking unit. More particularly, the present invention relates to the injection of a reducing agent in combination with a readily-oxidizable gas into a regenerator off-gas stream to reduce at least a portion of the NO in the regenerator off-gas stream, then contacting the regenerator off-gas stream with an effective amount of a treating solution under conditions such that at least a fraction of the oxidizable NO_x species present in the regenerator off-gas stream is oxidized to higher oxides, and subsequently removing at least a fraction of these higher oxides from the off-gas stream. One embodiment of this invention also relates to the use of a reacted caustic solution from a wet gas scrubber for the removal of at least a fraction of the higher oxides.

The invention relates to a synthesis method for hydrocalumites and a hydrocalumites based PVC complex heat stabilizer. The synthesis method comprises the following steps: performing co-precipitation reaction on the water solution of calcium salt and the water solution of aluminium salt under the existence of soluble carbonate and caustic alkali, so as to synthesize hydrocalumites, wherein the calcium salt comprises hydrated calcium chloride, the aluminium salt comprises aluminium chloride and sodium metaaluminate, the soluble carbonate comprises Na2CO3 or K2CO3, the caustic alkali comprises NaOH or KOH, and the typical structure of the hydrocalumites is Ca6Al2(OH)16CO3 . 4H2O and Ca4Al2(OH)12CO3 . 4H2O; preparing the hydrocalumites based PVC complex heat stabilizer from the hydrocalumites , calcium soaps, zinc soaps, a lubricant, a chelating agent and an antioxygen according to an appropriate proportion. Compared with the conventional PVC complex heat stabilizer, the hydrocalumites based PVC complex heat stabilizer provided by the invention has better preliminary hue and longer color-maintaining effect on the PVC and other superpolymers containing chlorine, and the long-term heat stability is excellent; besides, the PVC complex heat stabilizer has the characteristics of no toxicity, environmental protection, low cost, rich raw materials, and great convenience for manufacture and the like.

Bayer process, comprising grinding (L, B) and then digestion (N2, A) of a bauxite by bringing it into contact with a sodium aluminate liquor (20b, 120b). Digestion consists of forming a slurry (3a, 103) that is then treated to separate insoluble residues (5a, 105a) from the sodium aluminate liquor. The liquor is then crystallized (D) and recycled back to green liquor (20, 120) after having been separated from the alumina trihydrate (11, 111) precipitated during crystallization. The process comprises a predesilication treatment (P) during which the ground bauxite is brought before digestion into contact with an aqueous sodic solution that has a content of carbonates, sulphates and possibly chlorides which, expressed as a percentage related to the caustic concentration, is less than half the corresponding impurities content of the spent liquor (8, 108). Preferably, the pure caustic soda used to compensate for caustic soda losses in the Bayer circuit that was previously injected just after evaporation is now added in the aqueous sodic solution for the predesilication treatment.

Techniques for growing crystalline calcium carbonate solids such that the crystalline calcium carbonate solids include a volume of 0.0005 mm³ to 5 mm³, include a slaker to react quicklime (CaO) and a low carbonate content fluid to yield a slurry of primarily slaked lime (Ca(OH)₂); a fluidized-bed reactive crystallizer that encloses a solid bed mass and includes an input for a slurry of primarily slaked lime, an input for an alkaline solution and carbonate, and an output for crystalline calcium carbonate solids that include particles and an alkaline carbonate solution; a dewatering apparatus that includes an input coupled to the crystallizer and an output to discharge a plurality of separate streams that each include a portion of the crystalline calcium carbonate solids and alkaline carbonate solution; and a seed transfer apparatus to deliver seed material into the crystallizer to maintain a consistent mass of seed material.

The invention discloses a mixed phosphate and caustic alkali solution for preparing monocrystal textured surfaces, and relates to the technical field of preparation of solar cells, in particular to preparation of textured surfaces in production technology of monocrystal silicon solar cells. The mixed phosphate and caustic alkali solution is prepared from phosphates, caustic alkali and isopropanol.The solution overcomes the defects of uneven pyramid size, chromatic aberration on the surface of silicon wafers and the like which are caused by the prior monocrystal silicon etching corrosive solution. The solution uses the phosphates instead of silicates to obtain a different monocrystal silicon etching corrosive solution. Practice proves that the solution can be used for preparing textured-surface monocrystal silicon wafers with even size and uniform surfaces.

The invention discloses zinc-nickel alloy plating liquid, which comprises the following materials: 10 to 15 g/L of zinc oxide, 10 to 15 g/L of nickel sulfate hexahydrate, 75 to 100 g/L of caustic alkali, 15 to 25 ml/L of ethyliminum, 23 to 30 ml/L of triethanolamine, 0.5 to 3 g/L of urotropin, 0.05 to 0.5 g/L of vanillin, 1.0 to 5.0 g/L of saccharin and 0.1 to 0.6 mL/L of diethylhexyl sodium sulfate. After a zinc-nickel alloy is plated by the zinc-nickel alloy plating liquid, the obtained plating layer is silvery white, bright, smooth and compact, the nickel content is between 11 and 14, and the zinc-nickel alloy plating liquid has high corrosion resistance.

A process is provided for preparing a spent noble metal fixed-bed catalyst for precious metals recovery, comprising: a) adding the catalyst to a caustic solution to wash the spent catalyst and to make a wash slurry having an alkaline pH, wherein the spent catalyst has been in contact with chloroaluminate ionic liquid catalyst, and wherein the spent catalyst comprises from 5 to 35 wt % chloride; and b) filtering the wash slurry and collecting: i) a filter cake having from at least 70 wt % of the chloride in the spent catalyst removed and having the noble metals retained, and ii) a wash filtrate. Also provided is a filter cake comprising a washed consolidated cake having 40 to 75 wt % solids, a cake moisture content from 25 to less than 60 wt %, 0.1 to 1.5 wt % total noble metals, and a residual chloride content of from zero to less than 4 wt %.

The invention belongs to the technical field of ternary material precursor preparation, and particularly to a method for preparing lithium aluminate modified ternary anode materials based on spent lithium-ion battery cathode materials. The method comprises the steps that anode materials are separated from spent lithium-ion batteries; the anode materials are leached in a caustic solution and filtered; lithium carbonate is obtained by adding carbonate to filtrate; a filter cake is leached with sulfuric acid and leaching liquid is obtained; an adjustment solution is obtained by adjusting the molar ratios of nickel, cobalt and manganese in a leaching solution; the adjustment solution, an ammonia water solution and a caustic solution are flow into a reaction still together, and the ternary material precursor is prepared by coprecipitation; then the ternary material precursor is mixed with lithium carbonate for roasting, and ternary anode materials are obtained; and the lithium aluminate modified ternary anode materials are prepared by adding sec-butyl alcohol, lithium methoxide and the ternary anode materials in a mixture of ethyl acetoacetate, ethanol and water for reaction and roasting. The ternary anode materials have good structure stability, good electrochemical performance, lower production cost and high product quality, and realize the directional circulation of nickel-cobalt-manganese lithium resources.

The invention discloses an apple peeling agent, which comprises the following components in percentage by mass: 3% to 5% of caustic alkali, 0.5% to 0.8% of surface active agent, 0.2% to 0.3% of additive, and the balance of water. An apple is peeled by the peeling agent, the peeling can be completed at the temperature of 60 to 70 DEG C, the peeling rate is 100%, the browning difficultly occurs, the appearance is good, and the processing requirements of foods are met.

The invention relates to a preparation method of alkyl phosphite. The prepared alkyl phosphite can be used for a non-sulfide ore floatation collecting agent. The preparation method comprises the following steps: firstly adding fatty alcohol and water into a reaction kettle, slowly dropwise adding phosphorus trichloride at room temperature and continuously stirring, and reacting at 30DEG C-90DEG C after the dropwise addition of phosphorus trichloride is completed, wherein the fatty alcohol is linear-chain fatty acid alcohol of C6-C18, benzene ring fatty alcohol or different carbon chains of mixed alcohol; adding caustic alkali at 30DEG C-90DEG C and continuously stirring, and reacting for 0.5-1.5 hours at 30DEG C-60DEG C after stopping adding of the caustic alkali, thus obtaining the alkyl phosphate. The method for preparing alkyl phosphite is simple in production technology, low in the cost of raw materials, convenient for industrial production, and aiming at different types of ores, different alkyl phosphite can be prepared by changing raw materials fatty alcohol.

A process for the production of hypochlorite using a concurrent packed tower (10) to react caustic and chlorine as they pass concurrently through the tower. The packing may be either random packing or structured packing. The process may be either continuous or batch.