Patent GB-749662-A (GB)
Title: Process for the purification of liquids containing colloidal or suspended substances in very fine division
IPC: C02F1/52
Filed: 1953-12-24
Abstract: In a process for precipitating colloidal impurities from liquids, alkali huminate is added in such small proportion that fresh humic acid is formed from it; this is then distributed uniformly and a known precipitant added.  Where the liquid to be purified is not initially non-basic its pH value may be regulated to lie in the range extending from 4.5 to 7 inclusive.  The huminate is preferably mixed with the liquid to be purified in the form of a solution of huminate. Where the liquid to be purified is strongly acid the huminate solution is prepared from substances which have been boiled with nitric acid.  Examples given relate to the preservation of beer (Group VI), the removal of traces of precious metals (Group II), and the treatment of wastes from parchment factories, textile finishing works and tanneries (Group I), and from paper and felt-board factories (Group VIII).  Specification 15079/09 [Class 46] is referred to.ALSO:Alkali huminate is added in such small proportion that fresh humic acid is formed from it; this is then distributed uniformly and a known precipitant added.  Where the liquid to be purified is not initially non-basic its pH value may be regulated to lie in the range extending from 4.5 to 7 inclusive.  The huminate is preferably mixed with the liquid to be purified in the form of a solution of huminate.  Where the liquid to be purified is strongly acid the huminate solution is prepared from substances which have been boiled with nitric acid.  For the purification of tanneries waste water there is used alkali huminate produced by boiling brown coal with caustic soda.  After the addition of ferric chloride the solution flocculates.  To remove slimy substances from the waste sulphuric acids of parchment factories there is added sodium huminate prepared from nitrated brown coal, the humic acid formed being then precipitated as before.  Other examples p  relate to the preservation of beer, the removal of traces of precious metals, and the treatment of wastes from paper and felt-board factories and from textile-finishing works. Specification 15079/09, [Classes 46 and 113], is referred to.ALSO:In the purification of liquids alkali huminate is added in such small proportion that fresh humic acid is formed from it; this is then distributed uniformly and a known precipitant added.  In one example for removal of traces of precious metals from solutions or waste waters there are added from 50 to 150 grams of sodium huminate per cubic metre.  The content of metal salts may cause spontaneous flocculation of the humic acid formed; alternatively, other metal salts may be added to cause it.  The metals to be removed are flocculated at the same time.  Specification 15079/09, [Class 46] is referred to.ALSO:In the purification of liquids, alkali huminate is added in such small quantity, namely in the proportion of from 50 to 150 grams per cubic metre, that fresh humic acid is formed from the alkali huminate and is then distributed as uniformly as possible in the liquid before a known precipitant is added.  In an example, in order to preserve beer for the tropics, 50 grams sodium huminate per cubic metre are added and stirred in. After ten minutes the humic acid present is precipitated by another acid and separates out as flakes which carry the coarse albuminous substances down with them, while the finer albuminous substances remain in the liquid.  Specification 15079/09, [Class 46], is referred to.