Abstract: This invention relates to a method for preparing a Zinc Sulfide powder, and provides a method for preparing a single crystalline powder of Zinc Sulfide (ZnS) a high crystallinity comprising a step of conducting a hydrothermal reaction of a) Zinc Oxide or Zinc acetate as Zinc source and b) thioacetamide or thiourea as Sulfur source at a temperature of 180 to 230° C. and a fluorescent substance using the same as a source.

Abstract: Provided is a process for isolating zirconium peroxosulfate and its use, either as is or to prepare high purity zirconium compounds including powders of zirconium dioxide and stabilized zirconia. The process is based on precipitating a peroxide compound from an acidic peroxide solution of zirconium and provides a simple, economical method for producing the zirconium peroxosulfate powder and its derivatives with degree of zirconium recovery more than 99%. This process further provides an effective method for the separation and purification of zirconium from a variety of elements and/or naturally occurring ores.

Abstract: A method of using high temperature plasma to disintegrate waste containing titanyl phthalocyanine (TiOPc) comprises heating a mixture of titanyl phthalocyanine (TiOPc), a vitrifying material and optionally selected waste soil to a temperature of 1,220° C. to 10,000° C. until the mixture becomes a molten lava. The plasma breaks down the titanyl phthalocyanine and encapsulates the benign products in the lava that is chemically very stable. Since the titanyl phthalocyanine (TiOPc) is disintegrated completely in the process, the titanyl phtbalocyanine (TiOPc) no longer represents a threat to the environmental.

Abstract: Methods and apparatus are described which utilize an aqueous hydrogen peroxide composition of hydrogen peroxide and at least one additive which serves to catalyze the rapid decomposition of the hydrogen peroxide into hydroxyl radicals. When contacted with an atmospheric effluent containing odor and/or noxious components, the hydroxyl radicals formed oxidize the odor and noxious components to non-odor offensive, environmentally acceptable by-product.

Abstract: In a method of producing ferrous sulfate heptahydrate, ferrous sulfate monohydrate is converted in a crystallization reactor in the presence of water into ferrous sulfate heptahydrate as crystallized product, and water is subsequently isolated from the ferrous sulfate heptahydrate. Ferrous sulfate monohydrate is obtained from a pickling solution containing ferrous chloride, hydrochloric acid and water and reacted in a precipitating reactor in the presence of excess sulfuric acid to form ferrous sulfate monohydrate and hydrochloric acid. The ferrous sulfate monohydrate is then dehumidified and converted in a crystallization reactor in the presence of excess water into ferrous sulfate heptahydrate.

Abstract: Provided herein are monocomponent and hybrid catalyst compositions for use in steam-cracking of hydrocarbon feeds to selectively produce light olefins. The catalyst compositions being characterized by a first catalytic component comprising oxides of aluminum, silicon, chromium, and optionally, oxides of monovalent alkaline metals, and further comprising a binder, preferably bentonite clay. Preferably, the catalyst compositions will comprise a catalytic component in accordance with the following formula: (a) SiO2·(b) A12O3·(c) Cr2O3(d) alk2O, with alk being a monovalent alkaline metal, preferably selected from sodium, potassium and lithium. The second catalytic component is selected from a crystalline zeolite or a silica molecular sieve. Also provided in the present invention are methods of making the catalyst compositions.

Abstract: The present invention utilizes one or more processes to immobilize a waste that contains one or more of radionuclides, hazardous elements, hazardous compounds, and/or other compounds present in the waste. Each of the processes create a barrier against leaching and diffusion of the wastes. The first barrier is created by integrating the waste with an immobilizing mineral. The second barrier is a layer of non-radioactive or non-hazardous material that covers the first barrier. The second barrier may be created using an overgrowth procedure or by sintering. The third barrier is created by a rock or glass matrix that surrounds the first and/or second barriers. The fourth barrier is created by ensuring that the rock or glass has the same or similar composition as the indigenous rock at the disposal site. The resultant rock or glass matrix is in equilibrium with the groundwater or local hydrothermal solutions that are saturated with components of the indigenous rock of the disposal area.

Abstract: A method for chemically decontaminating radioactive material. The method includes reducing-dissolving step for setting surface of radioactive material in contact with reducing decontamination liquid including mono-carboxylic acid and di-carboxylic acid as dissolvent; and oxidizing-dissolving step for setting the surface of the radioactive material in contact with oxidizing decontamination liquid including oxidizer. The method may include repeated pairs of steps, each pair including the reducing-dissolving step and the oxidizing-dissolving step. The mono-carboxylic acid may include formic acid, and the di-carboxylic acid includes oxalic acid. The oxidizer may be ozone, permanganic acid or permanganate.

Abstract: A process for producing a vanadyl sulphate solution (VOSO4) comprises forming a suspension of vanadium trioxide (V2O3) in a sulphuric acid solution and contacting the V2O3 suspension with a strong oxidising agent under controlled conditions to produce the VOSO4 solution. A preferred oxidising agent is hydrogen peroxide, which is added very slowly to the V2O3 suspension due to the violent nature of the reaction.

Abstract: A process for preparation of an ammonium polythiomolybdate or a hydrate thereof of the formula (NH4)2Mo3S13.n H2O where n is 0, 1 or 2, in which aqueous ammonium monosulfide, elemental sulfur and molybdic oxide are reacted in a sealed reactor, with hydrogen sulfide gas being fed into the reactor until the hydrogen sulfide is no longer absorbed by the reaction mixture to form a reaction product and then heating the reaction product in a sealed reactor, the concentration of ammonium monosulfide in the reaction mixture being controlled throughout the reaction such that reactor pressure does not exceed 700 kPa (100 psig).

Abstract: A hydrocarbon gas such as methane and LPG is desulfurized in the presence of oxygen and an oxidation catalyst to convert sulfur compounds in the gas to sulfur oxides. The sulfur oxides are then trapped downstream of the oxidation by an adsorbent. The amount of oxygen added to the hydrocarbon gas to promote oxidation is such that the sulfur compounds are selectively oxidized and the oxidation of the hydrocarbon gas is minimized to reduce hydrogen formation.

Abstract: A mixed melt, which contains urea and/or a urea derivative and contains a sulfur source and a zinc source, is prepared. A temperature of the mixed melt is raised, and a precipitate of zinc sulfide is thereby formed. The temperature of the mixed melt is raised even further, and a solid material containing the zinc sulfide is thereby formed. The solid material is fired, and organic constituents contained in the solid material are thus removed. Zinc sulfide particles having uniform particle size and free from inclusion of impurities are thus produced without any precipitant being added.

Abstract: The process for the brightening of continuously produced sodium hydrogensulfate obtained in the reaction of sodium chloride and concentrated sulfuric acid in molten sodium hydrogensulfate in a circulation reactor, wherein evolved hydrogen chloride and heating gases generated by an immersion burner are withdrawn at various sites and seed crystals are added for a faster conversion of initially formed metastable phases, is that from 0.01 to 0.05% by weight of aluminium oxide and/or from 0.5 to 1.5% by weight of magnesium oxide and/or magnesium sulfate and, optionally, additionally calcium sulfate are added as seed crystals.

Abstract: The thermal combustion step of the modified Claus process is carried out in a water-wall boiler instead of a refractory-lined reaction furnace. The water-wall boiler replaces the conventional refractory-lined furnace and waste heat boiler when air, oxygen, or oxygen-enriched air is used as the oxidant. The acid gas combustion may be hydrogen sulfide-rich or hydrogen sulfide-lean with or without contaminants such as hydrocarbons and ammonia. Thermal combustion is performed in a single stage, without a recycle, for all levels of oxygen enrichment.

Abstract: A process for the production of liquid ferric sulfate from finely-divided ferric oxide, sulfuric acid and water in a closed reaction vessel at temperatures ranging from about 130.degree. C. to about 150.degree. C. and pressures from about 30 psi to about 70 psi. The reaction time ranges from Four to eight hours and produces liquid ferric sulfate having at least 10% trivalent iron. Yield and efficiency are provided by controlling the specific gravity prior to the reaction and by counter current cycling the waste stream from the reaction through the dilution water and use of a polymeric settling agent to remove unreacted iron content from the digester output.

Abstract: A method for preparing aluminum sulfate which comprises subjecting sulfuric acid and aluminum hydroxide to reaction, wherein the reaction is advanced in the presence of at least one member selected from the group consisting of nitric acid and a peroxide. An industrial composition comprising aluminum sulfate. By the method of the present invention, aluminum sulfate can be efficiently and commercially advantageously prepared. Further, the industrial composition of the present invention can be advantageously used in various industrial fields as, for example, a waste water treatment agent, a paper sizing agent, a tanning agent for hides, a clarifying agent for fats and oils, or a catalyst for industrial use.

Abstract: Reduced sulfur gas species (e.g., H2S, COS and CS2) are removed from a gas stream by compositions wherein a zinc titanate ingredient is associated with a metal oxide-aluminate phase material in the same particle species. Nonlimiting examples of metal oxides comprising the compositions include magnesium oxide, zinc oxide, calcium oxide, nickel oxide, etc.

Abstract: A process for removing hydrogen sulfide, other sulfur-containing compounds and/or sulfur and mercury from a gas stream contaminated with mercury, hydrogen sulfide or both. The method comprises the step of selective oxidation of hydrogen sulfide (H2S) in a gas stream containing one or more oxidizable components other than H2S to generate elemental sulfur (S) or a mixture of sulfur and sulfur dioxide (SO2). The sulfur generated in the gas stream reacts with mercury in the gas stream to generate mercuric sulfide and sulfur and mercuric sulfide are removed from the gas stream by co-condensation.

Abstract: A method for the automated production of liquid SO2 having a purity above 99.9% from elemental sulfur and pure oxygen, in the presence of SO2 recirculated from a closed circuit production system. The temperature of the combustion is controlled by means of pre-defined S, O2 and SO2 ratios. The automation is made based on oxygen sensors and on sulfur and SO2 flow meters with their respective control connections and proportional valves permitting a fine control of the sulfur combustion reaction. Liquefaction of gaseous SO2 produced is carried out alternatively by a cool plant working between ?10 and ?60° C. or with a compression unit working at a pressure between 3.8 and 5.0 bar. The automation permits an optimum temperature control and a clean production of SO2.

Abstract: A process for continuous production of ammonium thiosulphate, (NH4)2S2O3 (ATS) from NH3, H2S and SO2 is disclosed. A first feed stream comprising H2O, H2S and NH3 with a molar H2S:NH3 ratio <0.4 is partially condensed to form a condensate. The condensate is contacted with a third feed gas comprising H2S and the gas stream comprising NH3 and H2S is passed to a mixing device where the gas stream is dissolved in water drained off from an aerosol filter. A second feed gas stream comprising approximately ? mole SO2 per mole of NH3 contained in the first feed stream is passed to a SO2 absorber. The aqueous solution produced in mixing device is contacted with the SO2 absorber.