摘要:
A method of extracting a substantial proportion of the pyritic, organic, and sulfate sulfur compounds and ash present in a solid carbonaceous fuel of the coal or coke type comprising mixing the fuel with an aqueous alkaline solution containing a sodium, calcium, or ammonium carbonate, hydroxide, sulfide, or hydrosulfide, or a plurality thereof, heating the resulting mixture to at least about 125.degree. C at a pressure of at least about 25 psig to leach out the sulfur compounds and ash, separating the easily removable leached out materials from the remainder of the fuel, and washing said remainder of the fuel. The concentration of alkali in the solution typically is about 1 to 35 percent by weight, and the mixture typically is heated for at least about 5 minutes at about 350.degree. C, about 1 hour at 300.degree. C, about 2 hours at 250.degree. C, about 4 hours at 200.degree. C, about 10 hours at about 125.degree. C, or for at least a time approximately proportionately between the foregoing times at an intermediate temperature. The pressure may be provided at least in part by oxygen, hydrogen, nitrogen, oxygen plus nitrogen, or hydrogen plus nitrogen.
摘要:
Fine particles of a solid carbonaceous fuel of the coal or coke type are treated to reduce their content of undesired constituents at least including sulfur or ash or both. The treatment comprises forming a mixture of the fuel particles with a liquid aqueous leaching solution, containing one or more cations selected from Groups IA and IIA of the periodic table, which is effective to dissolve the undesired constituents. The mixture is exposed to temperatures in the range of about 150.degree. to 375.degree. C under a pressure of at least the autogeneous steam pressure until the solution has dissolved the undesired constituents of the fuel to such an extent that the undesired constituent content of the fuel particles has been reduced to less than a desired limit. The major portion of the solution is then separated from the fuel particles under temperature and pressure conditions and within a time period such that the amount of the undesired constituents dissolved in the solution is not substantially reduced by precipitation, adsorption on the fuel particles, or chemical recombination therewith. The separation is typically carried out by filtering the solution to remove the solid fuel particles. The temperature of the mixture is typically maintained in the range of about 100.degree. to 375.degree. C during the separation step, desirably at about the same temperature and pressure as those used during the dissolving step.
摘要:
A method of treating fine particles of solid carbonaceous fuel of the coal or coke type that comprises mixing the fuel particles with a liquid aqueous solution comprising essentially (a) sodium, potassium, or lithium hydroxide together with (b) calcium, magnesium, or barium hydroxide or carbonate, or a plurality thereof, with a ratio of (a) to the fuel of about 0.04 to 0.70 (typically 0.10 to 0.35) by weight, a ratio of (b) to the fuel of about 0.02 to 0.30 (typically 0.08 to 0.20) by weight, and a ratio of water to the fuel of about 1 to 10 (typically 2 to 5) by weight; heating the resulting mixture, at an elevated pressure, to a temperature of about 150.degree. to 375.degree. C (typically 175.degree. to 300.degree. C) in such a manner as to improve the usefulness of the fuel particles; and cooling to below about 100.degree. C. The cooled mixture either is dried or filtered to separate the fuel particles from the solution, the particles then being washed and dried. The filtered solution is regenerated so that it can be again mixed with unreacted fuel particles. The solution typically comprises essentially sodium hydroxide and calcium hydroxide or carbonate, and may comprise also magnesium hydroxide or carbonate.
摘要:
Disclosed is a method of making particle which comprise hydrous trivalent chromium oxide having the empirical formula CrO.sub.2 H intimately associated with a pulverulent carbonaceous substrate. A composition is formed which comprises an aqueous solution of water-soluble hexavalent chromium compound and a reducing agent in an amount sufficient to reduce the hexavalent chromium compound to the hydrous trivalent chromium oxide and to reduce the hydrous trivalent chromium oxide to metallic chromium. The reducing agent comprises a water-insoluble pulverulent carbonaceous substrate. Chrome metal can be made by heating the particles at a temperature of about 1100.degree. to about 1400.degree. C.
摘要:
A process for treating solid particles (66) of a raw carbonaceous fuel (62) such as coal having an original sulfur content comprises producing (at 68) a slurry (74) of a quantity of the raw fuel particles and a liquid medium (70) comprising water, at least one alkali metal compound including a substantial amount of sodium or potassium sulfide or polysulfide or a combination thereof, and a catalytic agent (72) comprising calcium or magnesium oxide or carbonate, or dolomite. The slurry is subjected (in 78) for an effective period of time to elevated temperature and pressure effective with the alkali metal compounds and water to cause the medium to penetrate the microscopic structure of the particles and to chemically and physically incorporate a substantial amount of the catalytic agent into the structure. The readily separable medium is separated (at 84) from the fuel particles and the particles are washed (at 84,106) to produce a particulate fuel product (88,110) containing the incorporated catalytic agent. A substantial portion (90,94) of the separated medium is added (at 70) to the slurry produced as above. A sufficient quantity of the catalytic agent is added (at 72) to the medium or the slurry to replace the catalytic agent removed from the slurry with the particulate fuel product. More raw fuel particles (66) are added to the medium or the slurry. The foregoing steps are carried out continually with a multiplicity of new additions of the raw fuel particles and with a multiplicity of reuses of the separated medium to produce fuel product particles (88,110) containing a quantity of sulfur that is not less than the original sulfur content, in addition to the catalytic agent.
摘要:
A method of treating a solid carbonaceous material comprising essentially lignite or bituminous or subbituminous coal to provide therefrom finely dispersed solid particles substantially free of ash and sulfur, by mixing the solid material with a liquid aqueous alkaline solution comprising essentially a sodium, potassium, or ammonium hydroxide, hydrosulfide, or carbonate, or a plurality thereof; dissolving the material by heating the resulting mixture to a temperature in the range of about 125.degree. C to the critical temperature, at a pressure of at least about 25 psig, while maintaining a substantial portion of the mixture in the liquid state; separating from the resulting solution any undissolved coal, ash, and other solids; reducing the pH of the solution to less than about 9 to precipitate therefrom a powder comprising the carbonaceous material, with a substantial proportion of the ash and sulfur that had been in the starting material now remaining in solution; and separating the precipitated powder from the solution. Typically either the pH of the solution is gradually reduced to less than about 2 during a time of at least about 5 minutes, or the precipitated powder is washed with an acid solution having a pH of less than about 2.
摘要:
The invention is characterized by two main methods of producing stabilized or partially stabilized zirconia powders with controlled particle size by use of complexing agents and hydrothermal treatment. A further embodiment of the invention is characterized by a combination of the first two methods to produce powders containing more than one major particle size. The invention also allows use of low cost readily available starting material, controlled doping level and incorporation of dual constituents such as MgO, CaO; Y.sub.2 O.sub.3, MgO; or Y.sub.2 O.sub.3, CaO in the structure for production of stabilized zirconia. Triply stabilized zirconia containing Y.sub.2 O.sub.3, MgO and CaO may also be produced. A final embodiment of the invention allows the production of dually and triply stabilized zirconia by hydrothermal treatment without the use of complexing agents.
摘要翻译:本发明的特征在于通过使用络合剂和水热处理制备具有受控粒度的稳定或部分稳定的氧化锆粉末的两种主要方法。 本发明的另一个实施方案的特征在于前两种方法的组合以产生含有多于一种主要粒度的粉末。 本发明还允许使用低成本易得的起始材料,受控的掺杂水平和双组分如MgO,CaO的掺入; Y2O3,MgO; 或Y2O3,CaO在稳定氧化锆生产的结构中。 也可以生产含有Y 2 O 3,MgO和CaO的三稳态氧化锆。 本发明的最终实施方案允许通过水热处理生产双重和三重稳定的氧化锆,而不使用络合剂。
摘要:
An improved process for beneficiating titaniferous material whereby formation of fines during leaching of the titaniferous material is minimized. The titaniferous material and mineral acid reactants each are heated to an elevated temperature prior to admixing in the leaching operation. The heated reactants then are admixed in a leaching zone and further heated to a leaching temperature of from about 110.degree. C. to about 150.degree. C. The preheating causes at least a portion of the acid-soluble titanium values in the titaniferous material to be hydrolyzed upon dissolution and to form an acid-insoluble precipitate. At least a portion of the precipitate is caused to deposit upon the titaniferous material such that fines or slime formation in the leach liquor is minimized. The leaching is continued for a sufficient time to dissolve most of the acid-soluble impurities contained in the titaniferous material. The solid residue remaining in the leaching zone is recovered as the beneficiated product.