摘要:
The object of the invention is a process for recycling used lubricating oils. After drying and gasoline removal, the oil is distilled and then treated with sodium or sodium hydride in a finely-divided state at elevated temperature. This is followed by a further distillation. Both distillations are at temperatures below 300.degree. C., the oil fractions of low volatility being respectively distilled in a molecular distillation apparatus at below 2 mbar.
摘要:
A method for reprocessing used lubricating oils is disclosed wherein the oil is dried, treated with finely dispersed sodium metal at elevated temperature, the remaining free or organically bound metal is decomposed by means of an active hydrogen containing compounds, followed by distillation of the oil for recovery.
摘要:
Gypsum plaster having a delayed setting time is made by adding a mixture of mesotartaric acid and l-tartaric acid or d,l-tartaric acid or a mixture of l-tartaric acid and d,l-tartaric acid to the gypsum plaster.
摘要:
There is described a process for the production of inert solvent soluble metal alcoholate free from alcohol of crystallization by reacting an alkali metal with an alcohol in an inert solvent above its melting point in an emulsion of the alkali metal in a solvent.
摘要:
Industrial gypsum plaster (plaster of Paris) having a delayed setting time is prepared by including D,L-tartaric acid and sufficient calcium hydroxide that a 5 weight % aqueous suspension of the plaster has a pH of at least 11.5.
摘要:
A process is described for leaching gold and/or silver from ores or ore concentrates using an aqueous alkaline cyanide solution with addition of hydrogen peroxide. The addition of the aqueous H.sub.2 O.sub.2 solution is regulated and controlled through the concentration of the oxygen dissolved in the leaching solution, the leaching solution containing from 2 to 20 mg O.sub.2 and preferably from 7 to 13 mg O.sub.2 per liter. 0.5 to 5% by weight H.sub.2 O.sub.2 solutions are preferably added. The process is applicable both to leaching by agitation and to heap leaching, the addition of H.sub.2 O.sub.2 being regulated and controlled through measurement of the O.sub.2 concentration in the leaching solution and can also involve measurement in a measuring stream. Despite low consumptions of H.sub.2 O.sub.2 and NaCN, the gold yield is even increased in some cases and the leaching time shortened.
摘要翻译:描述了一种使用加入过氧化氢的碱性氰化物水溶液从矿石或精矿中浸出金和/或银的方法。 通过溶解在浸出溶液中的氧浓度调节和控制H 2 O 2水溶液的添加,浸出溶液含有2至20mg O 2,优选7至13mg O 2 /升。 优选加入0.5-5重量%的H 2 O 2溶液。 该方法适用于通过搅拌和堆浸浸出,通过测量浸出溶液中的O 2浓度来调节和控制H 2 O 2的添加,并且还可以涉及测量流中的测量。 尽管H2O2和NaCN的消耗量很低,但在某些情况下,金的产量甚至增加,浸出时间缩短。
摘要:
This invention pertains to a method of treating cyanide contained in wastewater with particularly high levels of solids in the stream. The process involves either simultaneous or step-wise dosage of hydrogen peroxide in the form of an aqueous solution of a concentration between 35% to 90% by weight, preferably at least 50% by weight, and SO.sub.2 either in the form of gaseous SO.sub.2 or solution of sodium and/or potassium sulfite or metabisulfite resulting in the conversion of cyanide ions to non-toxic cyanate ions.
摘要:
Cadmium (Cd.sup.++) ions are separated from an effluent containing complexing agent such as nitrilotriacetic acid, ethylenediamine tetraacetic acid and/or diethylenetriamine pentaacetic acid, or their anionic salts by using an HS-containing triazine compound and Fe.sup.+++ ions in a quantity at least equal to the amount of complexing agent.
摘要:
A process for leaching gold and silver from ores and ore concentrates is disclosed using a cyanide leaching solution and hydrogen peroxide and maintaining an oxygen concentration of 2 to 20 Mg of O.sub.2 /liter. In the invention, leaching takes place in the presence of decomposition catalysts and preferably the formed cyano-complexes are separated during leaching from the leach solution. Decomposition catalysts are manganese compounds, present as 0.01 to 1 mg computed as Mn/liter of barren solution, or 1 to 50 mg computed as Mn per kg of ore slurry, or they are inorganic or organic polymers or carbon. Activated charcoal is preferred and simultaneously adsorbing cyano-complexes of precious metals. The process offers lowered consumption of H.sub.2 O.sub.2 and possibly cyanide and maximum gold yield in a shortened leaching time.