摘要:
The invention relates to a process for separating seminoble and/or noble metals from an aqueous solution having compounds of these metals dissolved therein by subjecting the solution to reaction with red phosphorus. More particularly, the solution is conveyed through a zone containing a layer of granular red phosphorus particles with a size of 0.01 to 10 mm, which may be used in admixture with active carbon.
摘要:
The disclosure relates to a process for removing nitrogen dioxide from off-gas. To this end, the disclosure provides for the off-gas to be intimately contacted with a suspension consisting of red phosphorus and a liquid being inert with respect to red phosphorus, e.g. water.
摘要:
The invention relates to a process for making red phosphorus by subjecting molten yellow phosphorus to a thermal conversion reaction in a closed reaction zone. To this end, a hollow shaft-provided and closed ball mill is preheated to a reaction temperature within the range 280.degree. to 590.degree. C. Yellow phosphorus is continuously introduced into the ball mill through the hollow shaft in quantities per unit time which permit the reaction temperature prevailing inside the ball mill to be maintained without supply of heat from the outside. More particularly, decreasing quantities of yellow phosphorus are introduced per unit time at increasing temperature and increasing quantities of yellow phosphorus are introduced per unit time at decreasing temperature within the limits specified. Red phosphorus is allowed to cool inside the ball mill, water is poured over it and the whole is subjected to wet-grinding. An aqueous suspension of red phosphorus is finally removed from the ball mill.
摘要:
The invention relates to a process for separating seminoble metals or noble metals from aqueous solutions having compounds of these metals dissolved therein, by reaction with yellow phosphorus. More particularly the aqueous solutions are contacted with carrier material having a yellow phosphorus coating applied thereto.It is possible for the aqueous solutions to be conveyed through a zone having the yellow phosphorus-coated carrier material placed therein, and for them to be subsequently conveyed through a further zone having uncoated carrier material placed therein.
摘要:
Manganese(II)salt solutions containing ammonium salt are made by subjecting a manganese-containing compound to processing treatment with an ammonium salt solution. A boiling temperature of 57.degree.-68.degree. C. is established in the suspension to be subjected to the processing treatment, by application of a vacuum. The ammonium salt solution used contains 0.5-2.5 mol/l diammonium sulfate or 1.0-5.0 mol/l ammonium nitrate.
摘要:
The invention relates to an apparatus for making red phosphorus by subjecting molten yellow phosphorus to a thermal conversion reaction in a closed reaction zone. To this end, a hollow shaft-provided and closed ball mill is preheated to a reaction temperature within the range 280.degree. to 590.degree. C. Yellow phosphorus is continuously introduced into the ball mill through the hollow shaft in quantities per unit time which permit the reaction temperature prevailing inside the ball mill to be maintained without supply of heat from the outside. More particularly, decreasing quantities of yellow phosphorous are introduced per unit time at increasing temperature and increasing quantities of yellow phosphorus are introduced per unit time at decreasing temperature within the limits specified. Red phosphorus is allowed to cool inside the ball mill, water is poured over it and the whole is subjected to wet-grinding. An aqueous suspension of red phosphorus is finally removed from the ball mill.
摘要:
Phosphine is continuously produced by reacting yellow phosphorus with an aqueous alkali metal hydroxide solution in the presence of an alcohol, with the exclusion of oxygen, at 44 to 90.degree. C. To this end, the reaction is effected in two separate reaction stages. In the first reaction stage, the alkali metal hydroxide solution and phosphorus are reacted with agitation in a molar ratio of 0.7:1 to 0.9:1 and the resulting gaseous phosphine is collected. Resulting liquid phase material containing unreacted phosphorus is delivered to the second reaction stage in which the unreacted phosphorus is reacted with further aqueous alkali metal hydroxide solution. The resulting gaseous reaction products are collected separately from the gaseous phosphine collected in the first reaction stage.
摘要:
Phosphine is produced from elementary yellow phosphorus and an aqueous alkali metal hydroxide solution in the presence of an alcohol. The phosphine is more particularly made by using an alcohol having from 5 to 10 carbon atoms and a dissolving power for yellow phosphorus of more than 5 g/l; suspending the phosphorus with agitation in the said alcohol in a reaction zone; reacting the resulting suspension with the alkali metal hydroxide solution at temperatures lower than the boiling point of the alcohol; and collecting the resulting issuing gaseous phosphine.
摘要:
An aluminum nitride powder has a crystallite size of 40 to 150 nm, measured by powder diffractometry and evaluated by the method of Scherrer, a primary particle size of 0.1 to 0.5 .mu.m, a specific surface according to BET of 5 to 50 m.sup.2 /g and a degree of whiteness of more than 91%, measured using light of a 400 to 700 nm wavelength against barium sulfate analytical reagent as standard of whitness.To prepare this aluminum nitride powder, metallic aluminum and monoamminealuminum chloride [AlCl.sub.3 (NH.sub.3)] are first molten together in an inert gas atmosphere at temperatures above 125.degree. C. and allowed to react with one another with evolution of hydrogen. 8 to 20 g of ammonia are then introduced per hour per mol of monoamminealuminum chloride into the aluminum-containing monoamminealuminum chloride melt at temperatures between 250.degree. and 400.degree. C., aluminum nitride being precipitated as a solid until the conversion of the aluminum is complete. The temperature of the melt is finally raised to more than 400.degree. C.
摘要:
The invention relates to the continuous production of phosphine. To this end, elemental phosphorus is reacted with an aqueous alkali metal hydroxide solution and at least one alcohol, the reactants being used in admixture with 0.01 to 2 weight % of a surfactant, the percentage being based on the alcohol.