44results about "Calcium/strontium/barium sulfites" patented technology

The invention relates to a flue-gas desulphurization system and a flue-gas desulphurization method. The flue-gas desulphurization system comprises a desulphurization absorbing tower connected with a limestone slurry feeding pipe, a flue-gas pipeline, a cloth-bag dust remover, a two-stage mist remover, a blower, a slurry discharging pump I and a hydraulic cyclone connected with the slurry discharging pump I, and is characterized in that the hydraulic cyclone is also connected with a slurry discharging pump II and a filtering machine; and the slurry discharging pump II is also connected with a dewatering screen which is also respectively connected with the filtering machine and a gypsum stockpile. The flue-gas desulphurization method comprises the following steps that: flue gas is dissolved in limestone slurry and then oxidized and crystallized to form gypsum slurry; and the gypsum slurry is concentrated by the hydraulic cyclone, the underflow of the hydraulic cyclone is pumped into the dewatering screen for dewatering by the slurry discharging pump II, and the overflow of the hydraulic cyclone is fed into the filtering machine for filtering. According to the flue-gas desulphurization system and the flue-gas desulphurization method, since the filtering machine and the dewatering screen are additionally arranged behind the hydraulic cyclone of the flue-gas desulphurization system and the dewatering screen is adopted for dewatering, so that the problem of difficult dewatering of the gypsum is effectively solved and the additional value of a gypsum product is high.

A chemical looping combustion (CLC) process for sour gas combustion includes a number of reaction zones and is configured to provide in-situ oxygen production and in-situ removal of S02 from a product gas stream by reacting the SO2 with a calcium-based sorbent at a location within one reaction zone. The CLC process is also configured such that the in-situ oxygen production results from the use of a metal oxide oxygen carrier which is purposely located such that it does not directly contact the sour gas, thereby eliminating the generation of undesirable sulfur-based metal oxides.

The invention provides a desulfurization and denitrification system and method by adopting ozone oxidation in cooperation with an ammonia method. The desulfurization and denitrification system comprises a first absorption device and a second absorption device which are sequentially communicated in the flue gas flow direction. An ozone generation device is connected into an inlet flue of the firstabsorption device; the interior of the second absorption device is sequentially divided into a circulating spraying area and at least two layers of multi-effect spraying areas from bottom to top in the flue gas flowing direction, the circulating spraying area is externally connected with at least two absorbent storage tanks, the absorbent storage tanks are independently connected into the multi-effect spraying areas respectively, and the absorbent storage tanks supply absorbents to the circulating spraying area and the multi-effect spraying areas respectively; and the circulating spraying areais externally connected with a recovery unit. By adopting a double-tower structure for absorption, the retention time of the absorbent in the tower is prolonged, the contact time with flue gas is prolonged, and the desulfurization and denitrification efficiency is improved. A mixed absorbent of ammonia water and a calcium-based absorbent is adopted, and NOx in the flue gas is converted into chemical fertilizer and gypsum with higher additional value.

A process is developed wherein sodium carbonate is reclaimed from Trona-treated fly ash waste stream, and the fly ash rendered suitable for use as a Pozzolan. The process is a closed system wherein all separated aspects of the waste stream are reused by the generating power plant or offered as a commercial product.

The invention relates to the technical field of comprehensive utilization of inorganic chemical lithopone manufacture waste lead skim, in particular to a method for preparing calcium sulfite by utilizing sulfur dioxide waste gas. In the invention, calcium oxide is mainly utilized to treat released sulfur dioxide gas while lithopone waste residue heavy metals are extracted by utilizing an electric arc furnace technique, and the gas is applied to prepare a calcium sulfite product. The invention not only eliminates the toxic sulfur dioxide gas but also prepares the valuable product, reduces the pollution of the waste gas to the environment and meanwhile prepares the valuable product, thereby having obvious social benefits and economic benefits; and especially, the process and the production equipment are simple, thereby the method is a comparatively practical treatment and utilization method.

The present application pertains to methods for making metal oxides and/or citric acid. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation—carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation—carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth—bisulfite and aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

The invention relates to the technical field of disposal of combustible industrial solid wastes, in particular to a disposal system and a disposal method for combustible industrial solid wastes. The disposal system comprises a circulating fluidized bed boiler, a crushing and conveying device, a furnace feeder, a bed material conveying device, a two-stage SNCR denitrification device and a flue gastreatment subsystem; a gas inlet pipeline of a "J" valve returner of the circulating fluidized bed boiler communicates with a material return fan; flue gas outlets of two cyclones each communicate with a shaft flue at the tail part of the circulating fluidized bed boiler through a pipeline; and a high-temperature superheater, a low-temperature superheater, a coal economizer and a horizontal air preheater from are sequentially arranged from top to bottom at the shaft flue. The disposal system provided by the invention solves the problem of disposal of industrial solid wastes and does not need to burn other fuels such as coal, oil and natural gas in a normal combustion process; the ash and deacidified ash produced in combustion are both general wastes that can be comprehensively utilized; and the deacidified and dust-removed flue gas meets the ultra-clean emission requirements.

The present application pertains to methods for making metal oxides and/or citric acid. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation-carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation-carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth-bisulfite and aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

The invention relates to a method for preparing roasted sulfate residues into sulfites by using a chemical method. The method comprises the following steps: putting roasted sulfate residues and hydrochloric acid in a pure mass ratio of 1: (1.95-2.35) in a first corrosion-resistant reactor, and starting an agitator to stir for 20 minutes; then reacting to generate chlorides such as aluminium chloride, ferric chloride, calcium chloride, magnesium chloride and the like; filtering to obtain silicides and black filter cakes of elementary sulfur as well as a clear chloride liquid at the same time; feeding the obtained chloride liquid and sulphurous acid in a pure mass ratio of 1: (0.54-0.94) to a second corrosion-resistant reactor, starting the agitator to stir, reacting to generate a mixed liquid of calcium sulfite, magnesium sulfate and hydrochloric acid, and then filtering to obtain white filter cakes; and carrying out washing and drying, winnowing classification and smashing package on the white filter cakes so as to respectively obtain calcium sulfite and magnesium sulfate products, and simultaneously, returning the obtained clear diluted hydrochloric acid back to the former process for cycle utilization. In the invention, the sulfites are prepared by using the roasted sulfate residues as raw materials.

The invention relates to white carbon black prepared from industrial waste slag and a production technology thereof. The production technology is characterized by comprising the following steps of adding quartz sand, calcium sulfate and charcoal into a kiln furnace, reacting, and treating generated solid and sulfur dioxide by the following steps so as to generate calcium silicate, calcium sulfiteand calcium bisulfite: (1) generation of calcium silicate: dissolving the generated solid, precipitating and filtering, adding sulfuric acid, washing, pulping and drying, so as to obtain the calcium silicate; (2) generation of calcium sulfite: adding sodium carbonate into a calcium bisulfite solution, generating a calcium sulfite solution, and concentrating and drying one part to obtain the calcium sulfite; enabling the other part and the generated sulfur dioxide to react, generating a calcium bisulfite solution, and recycling to obtain the calcium sulfite; (3) generation of calcium bisulfite:adding sodium carbonate into the calcium bisulfite solution, generating the calcium sulfite solution, reacting with the generated sulfur dioxide, crystallizing, and drying, so as to obtain the calcium bisulfite. The production technology provided by the invention has the advantages that the process is simple, multiple types of products are jointly produced, the production cost is low, and the application and popularization value is higher.

A method for releasing impurities from a calcium-based mineral is described. The method comprises reacting a calcium-based mineral containing impurities with an aqueous solution of one or more ionic salts at a temperature of approximately 85 degrees centigrade or above, wherein at least one of the calcium-based mineral and the one or more ionic salts comprises sulphate and at least one of the calcium-based mineral and the one or more ionic salts comprises ammonium, and wherein the concentration of the solution is approximately 25% or higher mass fraction, such that double salt crystals are formed and impurities are released. The method further comprises separating the double salt crystals from the impurities. Various products of the process are also described.

The invention belongs to the technical field of treatment and utilization of three wastes (waste gas, waste water and waste residues) in the chemical industry, and particularly relates to a method for preparing sodium phosphate and barium chloride with cogeneration of a powdery barium salt by using salting-out master liquid generated in a zinc powder method. In the invention, by mainly utilizing the salting-out master liquid, which is generated in a process of preparing sodium hydrosulfite by using the zinc powder method, for treating barium phosphate, not only can sodium phosphate, barium chloride and powdery barium salt products with economic values and better purity be produced, but also the three wastes are hardly discharged to cause pollution, and a semi-finished product of detergent can even be recycled for dissolving raw materials. The method disclosed by the invention not only has the advantage of simple production process and equipment and low cost, but also can be used for effectively treating the environment pollution caused by the salting-out master liquid generated when the zinc powder method is used for preparing the sodium hydrosulfite, and is beneficial to creation of considerable economic benefits at the same time.

The invention relates to a preparation method of calcium sulfite particles having an amorphous structure. The method comprises: preparing certain concentrations of lime milk and a sodium hexametaphosphate solution with water, respectively, performing filtration with a filter membrane to remove undissolved impurities, adding a certain amount of the sodium hexametaphosphate solution to lime milk, performing continuous stirring for uniform mixing, adding calcium sulfite to adjust pH of the obtained solution to 6.8-7.2, and performing slow stirring to generate calcium sulfite. The generated calcium sulfite precipitation is filtered and centrifuged and is subjected to alternative washing with secondary distilled water and absolute ethanol, and the obtained product is subjected to full drying at 60 DEG C. Crystal structure detection by XRD (X-ray diffraction) and morphology observation by SEM (scanning electron microscope) are carried out to obtain the amorphous calcium sulfite particles. The obtained calcium sulfite particles have an amorphous crystal structure, have the particle size of 600-800 nm, and are uniform in preparation process. The calcium sulfite particles are simple in preparation process and low in cost, are safe and non-toxic in raw materials, and have a good turbidity removal effect on sugarcane juice.

The invention belongs to the technical field of treatment and utilization of three wastes (waste gas, waste water and waste residues) in the chemical industry, and particularly relates to a method for preparing caustic soda and calcium chloride with cogeneration of a powdery calcium salt by using salting-out master liquid generated in a zinc powder method. In the invention, by mainly utilizing the salting-out master liquid, which is generated in a process of preparing sodium hydrosulfite by using the zinc powder method, for treating calcium hydroxide, not only can caustic soda, calcium chloride and powdery calcium salt products with economic values and better purity be produced, but also the three wastes are hardly discharged to cause pollution, and a semi-finished product of detergent can even be recycled for dissolving raw materials. The method disclosed by the invention not only has the advantage of simple production process and equipment and low cost, but also can be used for effectively treating the environment pollution caused by the salting-out master liquid generated when the zinc powder method is used for preparing the sodium hydrosulfite, and is beneficial to creation of considerable economic benefits at the same time.