摘要:
In an aqueous fluid dispersible filler or pigment suspension containing a dispersion aid, the improvement which comprises employing as the dispersion aid about 0.01 to 1% by weight, based on solids, of a phosphonocarboxylic acid or a salt thereof. The pigment may be TiO.sub.2 and be present in from 30 to 80% concentration. The dispersion aid may be phosphonobutane-1, 2,4-tricarboxylic acid or a salt, and an amine or alkanolamine may also be present.
摘要:
A process for the removal of dust and sulphur dioxide from hot exhaust gases which have a low hydrogen halide content and the reheating of the purified exhaust gases, wherein(a) the hot exhaust gases are cooled to temperatures below 135.degree. C. by scrubbing with sulphuric acid,(b) sulphuric acid containing solids and dissolved metal sulphates is then separated from the exhaust gases from (a),(c) the exhaust gases from (b) are cooled to temperatures of 50.degree. to 70.degree. C. by scrubbing with 15 to 50% sulphuric acid,(d) and desulphurized with the formation of sulphuric acid,(e) and reheated to temperatures of 70.degree. to 90.degree. C. by scrubbing with 50 to 65% sulphuric acid while the sulphuric acid discharged from (c) is concentrated and(f) the sulphuric acid from stage (a) together with the solid particles contained therein is cooled with the pure sulphuric acid from (e) in heat exchangers.The process according to the invention is particularly suitable for the purification of hot exhaust gases which are at a temperature of 170.degree. to 500.degree. C.
摘要:
A process for the preparation of sulphur dioxide by the thermal decomposition of metal sulphates in a fluidized bed reactor with sulphur-containing reducing agents and energy suppliers, characterized in that a mixture comprising the metal sulphates, the sulphur-containing reducing agents and 75 to 99% of the energy suppliers is fed into the fluidized bed reactors and the remainder of the energy suppliers is introduced separately into the fluidized layer of the fluidized bed reactor.
摘要:
A process for the preparation of titanium dioxide by the sulphate process in which titanium raw materials are decomposed with sulphuric acid, the resulting titanyl sulphate is hydrolyzed, the waste acid is separated from the hydrolyzate and evaporated to a concentration of 60 to 70%, sulphuric acid is separated from the solid metal sulphates, and the sulphuric acid which has been concentrated by evaporation is used again for the decomposition of the titanium raw material, the improvement wherein the 60 to 70% sulphuric acid is concentrated to 70 to 80% H.sub.2 SO.sub.4 in a further evaporation stage and the concentration of a part of this sulphuric acid is raised to a concentration of 98 to 99% H.sub.2 SO.sub.4 by the absorption of SO.sub.3 and then used together with the remainder of the above-mentioned 70 to 80% sulphuric acid for the decomposition of titanium raw materials.
摘要翻译:通过硫酸盐工艺制备二氧化钛的方法,其中钛原料用硫酸分解,得到的硫酸氧钛被水解,废酸与水解产物分离并蒸发至60至70%的浓度,硫酸 酸与固体金属硫酸盐分离,通过蒸发浓缩的硫酸再次用于钛原料的分解,其中将60-70%硫酸浓缩至70-80%H 2 SO 4的改进 进一步蒸发阶段,通过吸收SO 3将该硫酸的一部分浓度提高至98至99%H 2 SO 4的浓度,然后与剩余的上述70-80%硫酸一起用于 分解钛原料。
摘要:
An improved process for the preparation of TiCl.sub.4 comprising(a) chlorinating a raw material containing titanium and vanadium impurities to produce a crude TiCl.sub.4 reaction product,(b) separating the crude reaction product into solid by-products and TiCl.sub.4 -containing liquid,(c) reacting the TiCl.sub.4 -containing liquid with a reducing agent whereby vanadium impurities are converted into solid compounds, and(d) separating TiCl.sub.4 from the solid vanadium compounds, is improved by adding solid products of the vanadium reduction reactions to the crude TiCl.sub.4 reaction product prior to the separating step (b).
摘要:
A process for the production of TiO.sub.2 pigments by the sulfate process by digestion of titanium-containing raw materials with sulfuric acid, hydrolysis of the titanyl sulfate formed, purification of the hydrolyzate and calcination of the hydrolyzate in rotary kilns, wherein the calcination conditions are regulated through adjustment of the SO.sub.2 content of the waste gases issuing from the rotary kilns used for calcination.
摘要:
In the production of dinitrotoluene by a two-stage reaction of toluene with nitric acid in the presence of sulphuric acid, wherein toluene is nitrated to mononitrotoluene in the first stage using spent acid from the second stage, and the mononitrotoluene is nitrated to dinitrotoluene in the second stage using concentrated spent acid from the first stage, the improvement which comprises concentrating spent acid under vacuum in an indirectly-heated evaporator and feeding mononitrotoluene into the superheated vapor of the evaporator.
摘要:
Process for the preparation of sodium fluoride from sodium hydroxide solution and hydrogen fluoride, characterized in that at least 45% strength by weight, in particular 50% strength by weight, sodium hydroxide solution and anhydrous hydrogen fluoride are introduced separately into a saturated NaF solution in which 4 to 50% by weight, preferably 5 to 30% by weight, solid NaF are suspended and the temperature of which is in the range from 20 to 80.degree. C., preferably 30 to 60.degree. C.
摘要:
A process for the thermal decomposition of metal sulphate mixtures at temperatures from 800.degree. to 1100.degree. C. under oxidizing conditions, in which the metal sulphate mixtures are mixed with roasting residue and reacted together with fuels in the decomposition reactor to form roasting residue and SO.sub.2 -containing gases from roasting wherein the roasting residue admixed with the sulphate mixture is the finely divided fraction of the resulting roasting residue which is separated from the stream of gas in an electrostatic gas purification apparatus and returned to the decomposition reactor.This procedure has an advantageous influence on the formation of coarse roasting residue and also significantly reduces the proportion of undecomposed, water soluble sulphates in the roasting residue.