Study On The Preparation Of Foam Glass And Mosaic Foam Glass From Boron Sludge

Boron sludge is a solid waste during production of borax. Each ton of borax production will bring four tons boron sludge discharge. Annually, millions of tons boron sludge is discharged in china, but there still lack of efficient recycling method at present. The borax sludge is usually put away to some certain place to restrict emission, causing big resource waste and environmental pollution. Now a new and scientific method to treat it is transforming the 40wt% MgO in boron sludge to MgCO₃ or Mg(OH)₂. However, the rest magnesium removal-sludge (about 50wt% of the total borax sludge) still causes pollution. By analyzing the component of magnesium removal-boron sludge, we speculate that foam glass can be prepared through commixing a fix quantify of deposed glass and magnesium removal-boron sludge. Foam glass is a kind of stick which is full of uniformity stoma, which has some excellent performance such as flame-resistance, light quality, high strength, heat and sound resistance, and thus is widely used in the following industry branch such as petroleum and construction. But when foam glass is used as constructional material, it can not be used for decoration because of its surface cellularity and color asymmetry. So we develop a composite mosaic foam glass which can be used both for heat preservation and decoration. Mosaic foam glass is a kind of material which has two layers—mosaic and foam glass.In the present work, a novel foam glass and mosaic foam glass which have high value has been prepared using magnesium removal-boron sludge and waste glass. The content of the paper mainly includes:(1) We introduce the preparation technology of foam glass. The best technological parameters for producing it is 600℃for sintering temperature, 30 min for sintering time, 790℃for foaming temperature, 10 min for foaming time, 35% for content of magnesium-removal boron sludge , 10% for content of forming agent, 10°C/min for elevating rate of the temperature and 3-5MPa for molding pressure.(2) The thickness matching between mosaic layer and foam glass layer of the mosaic foam glass was discussed. We find that when the thickness of mosaic layer is 25% of the composite, it has the best performance. (3) Finally, the economic feasibility analysis and environmental impact assessment were done for this novel borax sludge recycling technique. If we build a production line which produces foam glass 12000m3 per year, a fixed investment about 1500 thousand Yuan is needed, the net profit is about 750.8 thousand Yuan Per year and the annual rate of profit is about 124.5. The technique is environmental friendly which doesn't produce any solid waste. It has great profit in both society and economy.