Process for carrying out the junction of blocks of carbon for continuous electrodes, and the anode continues for the electrolysis of molten aluminium, produced according to this process

摘要

Dispersions of molybdenum sulphide are prepared by adding a solution of molybdenum compound to a lubricating oil detergent additive, or to a solution thereof in a lubricating oil, and passing hydrogen sulphide therethrough. Three methods are specified: (i) a molybdenum compound is dissolved in water preferably to form a saturated solution containing also hydrochloric or acetic acid or ammonium hydroxide and the solution (a) slowly added to the hot detergent or solution thereof in oil whilst maintaining the temperature at 250-600 DEG F. and bubbling through H2S or (b) added completely to the hot detergent or solution thereof and H2S then bubbled through the mixture; (ii) the aqueous solution of molybdenum compound is added to the detergent or solution thereof in the cold and H2S bubbles through; the resultant emulsion is then (a) broken by adding alcohol or salt and the organic layer separated and heated to remove water or (b) heated to remove all the water; and (iii) extracting an aqueous acidic solution of a molybdenum compound with an other or ketone, dispersing the extract in the detergent or solution thereof and then stripping the ether or ketone and sulphiding with H2S in a single step at up to 200 DEG F. (ethers) and 50-80 DEG F. (ketones); excess H2S is removed by vacuum or inert gas purge at up to 400 DEG F. The molybdenum sulphide produced by (iii) is a complex material containing such compounds as molybdenum blue and molybdenum oxides. Ethers specified are diethyl ether and tetrahydrofuran; ketones specified are methyl isobutyl, methyl isoamyl, methyl hexyl, diisobutyl, ethyl amyl, butyl ethyl and methyl isoamyl ketones and mixtures thereof. Specified molybdenum compounds are molybdates of ammonium, sodium, potassium, barium, magnesium, zinc and cadmium. Specified detergent additives are alkaline earth metal petroleum sulphonates ("mahogany acids"), alkaline earth metal and ammonium alkyl aryl sulphonates, alkyl phenates, alkyl phenate sulphides, metal carbonate sols, phosphosulphurized hydrocarbons and reaction products of metal oxides and/or hydroxides with phosphosulphurized hydrocarbons, many compounds of these types being particularized. Specified lubricating oils are mineral or synthetic oils including diesters, carbonate esters, glycol esters, complex esters, polysilicones and polyglycols. Numerous examples are given.ALSO:Compositions comprising a lubricating oil, molybdenum sulphide and a lubricating oil detergent additive wherein the molybdenum sulphide has been formed (see Division C1) by passing hydrogen sulphide through a mixture of a molybdenum compound solution and said detergent or a solution of said detergent in a lubricating oil, are suitable for use as lubricating oils or additives therefor. Specified types of detergent additives are alkaline earth metal petroleum sulphonates ("mahogany acids"), alkaline earth metal and ammonium alkyl aryl sulphonates, alkyl phenates, alkyl phenate sulphides, metal carbonate sols, phosphosulphurized hydrocarbons and reaction products of metal oxides and/or hydroxides with phosphosulphurized hydrocarbons, many compounds of these types being particularized. Specified lubricating oils are synthetic oils including diesters, carbonate esters, glycol esters, complex esters (e.g. as formed by reaction of sebacic acid, tetraethylene glycol and 2-ethyl hexanoic acid), polyglycol and polysilicones, but the numerous examples all relate to hydrocarbon oils. Other additives specified for various purposes are: a mixture of (a) polymethacrylate, (b) copolymer of "Lorol B" fumarate and vinyl acetate ("Lorol" is a Trade Mark), and (c) condensation product of chlorinated wax and naphthalene (as V.I. improver) and phenyl-a -naphthylamine, alkyl phenols and bis phenols (as antioxidants).