| 摘要 |
<p>The method for making a fresh cleaning fluid for a copper-plate printing machine. It involves using softened water, sulphonated ricin oil and caustic soda in proportions of 98.5 per cent, 1 per cent and 0.5 per cent respectively. After the fluid has been used it is subjected to ultrafiltration, producing a clear solution and a concentrated solution. The clear solution is recycled and the concentrated solution is flocculated to give solid residues and a filtered solution, the latter being neutralised, evaporated and distilled. The distilled water is used to make fresh solution, and the contaminated concentrated solution is used to make dry solid salts and a filtrate used for flocculation. The flocculant is made with the addition of calcium chloride and ferrous chloride, and the neutralisation is performed by hydrochloric acid with or without sulphuric acid.</p> |
