39results about How to "Alkaline concentration decreased" patented technology

The invention discloses a preparation method of tobermorite. The preparation method comprises the following steps: removing amorphous activated SiO2 in pulverized fuel ash by use of sodium hydroxide alkaline liquor so as to obtain a sodium silicate solution with an appropriate concentration, wherein the sodium silicate solution is used as a siliceous material; further performing hydro-thermal synthesis with refined lime milk to finally obtain a tobermorite product.

The invention discloses a method of producing mono-pentaerythritol, dipentaerythritol and tri-pentaerythritol. The adopted production raw materials comprise acetaldehyde and formaldehyde. An activator adopts liquid alkali. The liquid alkali is sodium hydroxide or calcium oxide; neutralization reagent adopts formic acid solution; the acetaldehyde and the formaldehyde are both dived into a pre-condensation kettle which is pressurized with inert gases. Reaction liquid reacts for a period in the pre-condensation kettle, and then the reaction liquid is shifted to a main condensation kettle which is pressurized with the inert gases to keep on reacting. The alkalinity of the reaction liquids in both reaction kettles is maintained to be different. The concrete method comprises the following steps: materials preparation, charging pre-condensation, the diversion of the reaction liquid, constant temperature condensation, neutralization and separation, etc. By adopting the technology, the yield rate of the dipentaerythritol is enhanced to 45 percent from existing 21 percent, and the main conversion rate of the acetaldehyde is more than 90 percent.

The invention discloses an alumina melting method. The melting method comprises the following steps: a. conveying primary ore pulp from a normal-pressure desiliconization process with the temperatureof 85-100 DEG C into a vapor preheater for preheating to 200-230 DEG C; b. conveying the ore pulp preheated by the vapor preheater into a molten salt heater for heating to 260-280 DEG C; c. conveyingthe ore pulp heated by the molten salt heater into an insulated melting tank for heat preservation for 30-45 minutes until a melting process is finished; d. conveying the melted ore pulp into a ore pulp self evaporator to decrease temperature and pressure; and e. conveying the ore pulp evaporated and concentrated in the self evaporator into a diluting tank, and diluting and mixing with a primary red mud washing fluid. The invention improves the heating temperature of the ore pulp to 280 DEG C, decreases the alkalinity of the primary ore pulp, saves the construction investment and equipment cost, reduces the energy consumption of an evaporation process, improves the utilization rate of secondary vapor heat, delays the scaring speed of a sleeve and decreases the equipment maintenance cost.

This method for producing a potassium perfluoroalkanesulfonate includes an electrochemical fluorination step in which an alkanesulfonyl halide compound is subjected to electrochemical fluorination in anhydrous hydrogen fluoride, thereby to generate a production gas containing perfluoroalkanesulfonyl fluoride as the main component. In addition, for example, the methods may include a gas absorption step in which the production gas is reacted with an aqueous solution of potassium hydroxide, thereby to generate a gas absorbed solution containing potassium perfluoroalkanesulfonate, a purification step in which impurities such as potassium fluoride, potassium hydroxide, and potassium sulfate, are removed, and a concentration and collection step in which the aqueous solution from which the impurities are removed is concentrated and dried. In the electrochemical fluorination, for example, it is possible that the proton concentration in the reaction solution is maintained in the range of 150 to 1,500 ppm to suppress the formation of byproducts.

A method for producing calcium carboxymethyl cellulose includes: soaking refined cotton in diluted hydrochloric acid, then neutralizing and activating the soaked refined cotton with diluted sodium hydroxide, enabling the prepared refined cotton to react with sodium chloroacetate so as to generate sodium carboxymethyl cellulose, displacing by hydrochloric acid and calcifying so that the calcium carboxymethyl cellulose is obtained finally. The method for producing the calcium carboxymethyl cellulose is simple in production process and operation, low in cost, small in wastewater generation quantity and less destructive to the environment.

The invention provides an electrochemical treatment method for arsenic-containing soot. The electrochemical treatment method comprises: (1) mixing an alkali and a solvent or mixing an alkali solutionand arsenic-containing soot to obtain a mixture; (2) placing the mixture as an electrolyte in an electrochemical reaction device, carrying out an electrochemical reaction, and introducing an oxidizinggas into the electrolyte during the electrochemical reaction; and (3) carrying out solid-liquid separation on the reaction product obtained in the step (2) to obtain the arsenic-containing solution.According to the present invention, the method has advantages of high extraction rate of arsenic, cleaning property, no pollution, mild process condition, low cost and low requirements on equipment; the impurity is not introduced so as to conveniently perform the subsequent separation; the concentration of the used alkali is low so as to reduce the alkali consumption; and the automation degree ishigh so as to reduce the manpower input, the good economic and social benefits can be provided, and the good application prospect can be provided.

The invention relates to the field of plant cultivation, and particularly provides a saline and alkaline land stock growing method and application. A plant pit is provided, a water filter layer, a decaying plant straw layer and a soil improving layer are successively laid on the bottom wall of the plant pit, a waterproof layer and a decaying plant straw layer are successively laid on a side wall of the plant pit, and a tube is inserted in the plant pit. The purpose of reducing saline concentration can be achieved, and time and conditions for stocks to adapt to the environment are provided. Meanwhile, the water filter layer facilitates water drainage; after the decaying plant straw layer are decayed deeply, acid can be formed, and the effect of reducing alkaline concentration of soil is achieved; by the soil improving layer, the survival rate of stocks can be improved while soil quality is improved; and the tubes not only can breath and drain water, but also has a heat-dissipation effect. The stock growing method is simple to operate, the labor and materials are saved, the cultivation cost is low, the method is environmentally friendly, the survival rate of the stock is high, effects of wind prevention and sand fixation are achieved, water resources are improved, and thus, the saline and alkaline land stock growing method can be applied to production and life on a large scale.

The invention provides an electrochemical treatment method for arsenic-containing smelting waste residue. The electrochemical treatment method comprises: (1) mixing an alkali and a solvent or mixing an alkali solution and arsenic-containing smelting waste residue to obtain a mixture; (2) placing the mixture as an electrolyte in an electrochemical reaction device, carrying out an electrochemical reaction, and introducing an oxidizing gas into the electrolyte during the electrochemical reaction; and (3) carrying out solid-liquid separation on the reaction product obtained in the step (2) to obtain the arsenic-containing solution. According to the present invention, the method has advantages of high extraction rate of arsenic, cleaning property, no pollution, mild process condition, low costand low requirements on equipment; the impurity is not introduced so as to conveniently perform the subsequent separation; the concentration of the used alkali is low so as to reduce the alkali consumption; and the automation degree is high so as to reduce the manpower input, the good economic and social benefits can be provided, and the good application prospect can be provided.

The invention relates to a method for hydrolyzing red mud, in particular to a method for reducing hydrolysis in a red mud separation and washing process in a Bayer process aluminum oxide production process. According to the method, dissolved ore pulp is directly injected into a separation tank by a final flash tank through self-pressing, washing water is added into a final washing tank, countercurrent washing is conducted for multiple times, overflow of a primary washing tank and overflow of the separation tank are mixed and then enter a coarse liquid tank, underflow of the separation tank enters the primary washing tank, underflow of each washing tank enters a next-stage washing tank, and red mud is finally discharged from a last-stage washing tank. According to the method, the alkali concentration of the ore pulp entering the separation tank is increased by 15-25g/L, and the degree of supersaturation of aluminum oxide is reduced by 5%-50%; a dilution tank and a dilution rear tank areomitted, the process is simplified, and investment and ore pulp conveying energy consumption are reduced; and the hydrolysis loss of alumina in the red mud separation and washing process is reduced by 50%, and the total recovery rate of the whole plant is improved.

The invention provides an alkaline activity inhibition material based on active sandstone aggregate and a preparation method of the alkaline activity inhibition material. By adopting the sandstone aggregate with potential alkaline activity, sandstone powder with the specific surface area of (645 to 950) m<2>/kg is prepared through twice grinding of a vertical mill and a ball mill, and the sandstone powder is uniformly mixed with medium heat cement and nano SiO2 in a certain proportion. The inhibition material is prepared from the following raw materials in percentages by weight: 75% to 87% of the medium heat cement, 10% to 20% of the sandstone powder and 3% to 5% of the nano SiO2. The alkaline activity inhibition material prepared in the invention has the technical advantages that the raw materials are easy to get, the machinability is good, the preparation technology is simple, the alkaline activity inhibition effect is obvious, and the preparation process is free of pollution to the environment, and is beneficial to large-scale production and application of engineering.

The invention discloses a use of tert-butyl hydroperoxide in preparation of a powdery coating removal composition and the coating removal composition. The coating removal composition comprises, by mass, 48 to 60% of dichloromethane, 15 to 30% of methanol, 15 to 25% of tert-butyl hydroperoxide, 1 to 2% of liquid paraffin and 0.2 to 1% of sodium hydroxide. The coating removal composition provided by the invention has the advantages of low cost, less pollution, short coating removal time and strong penetrability, can realize complete separation of the coating and a base and does not produce corrosion to the base. The coating removal composition provided by the invention also has strong depainting ability to the thick coating, is recyclable and reused after being soaked or rinsed, is especially suitable for removing the metal surface coating, comprises epoxy resin, polyurethane or acrylic resin, and can provide a technical support for development of an industrial cleaning agent.