COMPOSITION FOR PROTECTION AGAINST CORROSION AND SALT DEPOSITIONS IN WATER-SUPPLY SYSTEMS AND METHOD FOR PREPARATION THEREOF Russian patent published in 2000 - IPC

FIELD: corrosion protection. SUBSTANCE: composition contains, wt.%: phosphoric acid 66.5-72.5; sodium hydroxide and/or sodium carbonate (on conversion to sodium oxide) 14.5-19.5; calcium oxide or calcium hydroxide, or calcium carbonate, or their mixture (on conversion to calcium oxide) 6.5-9.5; magnesium oxide or magnesium hydroxide or magnesium carbonate, or their mixture (on conversion to magnesium oxide) 0.9-3.0; potassium hydroxide and/or potassium carbonate (on conversion to potassium oxide) 0.9-3.7; silicon dioxide or soluble glass (on conversion to silicon dioxide) 0.8-2.2. Preliminarily disintegrated calcium oxide or calcium hydroxide, or calcium carbonate, or their mixture and magnesium oxide or magnesium hydroxide, or magnesium carbonate, or their mixture are mixed with sodium hydroxide and/or sodium carbonate and potassium hydroxide and/or potassium carbonate. To resultant mixture is added water at stirring to form homogeneous suspension. The latter is filtered. Phosphoric acid is added to filtrate that is then stirred and heated to form syrupy stuff, to which preliminarily broken up silicon dioxide or soluble glass is added at stirring. Resulting material is kept being heated to achieve plastic state, after which it is melted at temperature not superior to 900 C. The melt is held at melting point for 10 to 30 min, stirred, and cooled with the rate 150 C/min. EFFECT: improved anticorrosion and antiscale properties at low concentration in water. 2 cl, 4 tbl