39results about How to "Avoid coprecipitation" patented technology

The invention relates to a method used for directly precipitating vanadium from an acid multi-impurity vanadium-containing solution. According to the technical scheme, the method includes the steps that an oxidizing agent is added into the vanadium-containing solution at first, oxidation is performed, and accordingly an oxidized vanadium solution is obtained; the addition amount of the oxidizing agent accounts for 1.0-2.5 times of the theoretical molar weight of an oxidizing agent required when low valent vanadium in the vanadium-containing solution is completely oxidized into pentavalent vanadium; then urea is added into the oxidized vanadium solution to be stirred according to the mass ratio of the urea to vanadium pentoxide in the oxidized vanadium solution being (3-20):1, solid-liquid separation is performed, and accordingly ammonium polyvanadate and vanadium precipitation mother liquor can be obtained; and afterwards, the ammonium polyvanadate is calcined for 0.5-3.0h at the temperature condition of 450-650 DEG C, and accordingly the vanadium pentoxide can be obtained. According to the chemical composition of the vanadium-containing solution, the vanadium concentration is larger than 6g / L, the aluminum concentration is smaller than 20g / L, the ferrum concentration is smaller than 1.0g / L, the sodium concentration is smaller than 30g / L, the potassium concentration is smaller than 2.0g / L, and the calcium concentration is smaller than 1.0g / L. The pH value of the vanadium-containing solution is smaller than 0.5. The method has the advantages that the technological process is short, the vanadium precipitating rate is high and the purity of the vanadium pentoxide product is also high.

The invention discloses a preparation method of a three-dimensional porous graphene-loaded nanometer magnesium-aluminum hydrotalcite fluorine removal agent. The preparation method comprises the following steps: (a) preparing the three-dimensional porous graphene; (b) preparing magnesium-aluminum solution, immersing the three-dimensional porous graphene in the solution; and (c) separating the immersed three-dimensional porous graphene, drying in a vacuum condition, adding into a carbon source weak base dilute solution, reacting, standing, aging, filtering, washing, and drying, so as to obtain the three-dimensional porous graphene-loaded nanometer magnesium-aluminum hydrotalcite fluorine removal agent. Due to the adoption of the method, the agglomeration characteristic of the magnesium-aluminum hydrotalcite prepared by a traditional method is overcome, the specific surface area of the nanometer magnesium-aluminum hydrotalcite is improved; meanwhile, because the carboxylic groups in the three-dimensional porous graphene are combined with the magnesium-aluminum atoms, the nanometer particles can be effectively limited into a porous channel of the three-dimensional porous graphene, losing of the nanometer material is avoided in a using process, and the material has a significant effect in fluorine-containing water treatment.

The invention relates to a method for producing zinc oxide through electrolytic zinc acid process leaching residues. The method comprises a primary digestion step, an optional purifying step, a desulfuration step, a calcium zincate synthesizing step, a primary calcining step, a secondary digestion step, a pressurizing and crystallizing step, a pressure reducing and decomposing step, an optional rinsing step and a secondary calcining step. According to the method, the problem about environmental protection is solved, secondary utilization of the leaching residues is achieved, pollution of multiple heavy metals is avoided, and meanwhile resource utilization of the leaching residues is achieved. Ammonia distillation is not needed, the method is simple, convenient and practical, and the energyconsumption of the process is greatly reduced. Sulfate ions as a pollution source are converted into wealth from waste through calcium sulfate, calcium zincate synthesis is achieved in a zinc ammoniaenvironment for the first time, zinc oxide is obtained from calcium zincate, the decomposing condition of ammonium carbonate is creatively utilized in the process, and recycling of carbon dioxide isachieved through differential pressure.

The invention relates to a method for producing nano zinc oxide by utilizing leaching residues of a zincic acid electrolysis method. The method comprises a primary extraction step, an optional purification step, a desulfurization step, a calcium zincate synthesis step, a primary calcination step, a secondary extraction step, a pressurizing and crystallization step, a decompression and decomposition step, an optional rinsing step and a secondary calcination step. According to the method disclosed by the invention, secondary utilization of the leaching residues is realized when environmental protection problems are solved; resource utilization is realized when various types of heavy metal pollution are solved; sulfate ions which are considered as a pollution source are changed into valuablethings through calcium sulfate transformation; the synthesis of the calcium zincate under a zinc-ammonia environment is realized for the first time; the nano zinc oxide is obtained through the calciumzincate; ammonia steaming is not needed and the method is simple and feasible; the energy consumption of a technology is greatly reduced; high-temperature and high-pressure potential safety hazards and equipment corrosion problems, which are caused by the ammonia steaming, are also avoided; decomposition conditions of ammonium carbonate are creatively utilized in the technology and cyclic utilization of carbon dioxide is realized through pressure difference.

The invention discloses a method for preparing a multi-stage nanocomposite material with photodegradable organic toxic gas, which comprises the preparation of porous layered nano-montmorillonite: the montmorillonite is pulverized to an average particle size of 50 to 50 by mechanical pulverization and air flow method. 200nm; preliminary preparation of nanocomposite materials: compound the montmorillonite and titanium-based photocatalyst materials at low temperature to obtain a compound, add the compound to water or alcohol, react at low temperature, and then add nitrogen source or carbon source for reaction , to obtain the primary nanocomposite material; multi-level nanocomposite material modification: after the primary nanocomposite material is cooled down, a modifier is added for modification, and the modifier accounts for the compound / water or alcohol / nitrogen source or carbon source 0.2-2% of the total mass of the system; the modifying agent includes glycerol or triethanolamine.

The present disclosure relates to a process for utilizing zinc-containing ore through a strontium zincate synthesis step, comprising a leaching step, an optional purification step, a decarburization step, a strontium zincate synthesis step, an optional rinsing step, and a drying or calcination step. The present disclosure realizes the synthesis of strontium zincate in the environment of zinc ammonia for the first time, and the reaction selectivity of synthesizing strontium zincate from zinc ammonium complex ions is high, simple and fast, and high value-added products are economically and environmentally friendly prepared from low-grade raw ores that are difficult to handle The disclosed method has a wide range of applications, can effectively extract and utilize various forms of zinc-containing raw ores, enriches zinc elements through the synthesis of strontium zincate, solves the problems of process recovery and high-quality goods grade, and the obtained products can be As a product directly, it can also be used as an industrial raw material.

The invention discloses a preparation method of high-purity magnesium saponite. The preparation method includes the steps that deionized water, water glass and sodium hydroxide are mixed and preparedinto a silicon-containing water solution; deionized water and magnesium salt are mixed and prepared into a magnesium-containing water solution; deionized water, aluminum salt, potassium salt, sodium hydroxide and sodium bicarbonate are mixed and prepared into an aluminum-containing water solution; under stirring conditions, the magnesium-containing water solution and the aluminum-containing watersolution are mixed firstly, so that mixed liquor is obtained; then the silicon-containing water solution is added into the mixed liquor, so that crystallizing liquor is obtained; the obtained crystallizing liquor is added into a crystallizing kettle for constant-temperature crystallization, then a mixture is cooled to have room temperature, and through centrifuging, washing, drying, smashing and sieving, the magnesium saponite is obtained. Under synergism of ion strength of a strong electrolyte solution, hydroxyl ions and carbonate ions, the alkalinity of the crystallizing liquor and the concentration of non-structure crystal ions are adjusted, the orienteering rate and clustering rate of structure crystal ions are coordinated, forming of a saponite crystal nucleus and crystal nucleus growth conditions are optimized, co-precipitation and after-precipitation are avoided, the purity of crystals is improved, and impurity forming is reduced.