Тechnology of multicomponent mixtures preparation
Glass batch is a multicomponent mixture of granular and fluid materials, to which increased requirements at one time in relation to exact dosing at high process capacity and to chemical and granulometric uniformity of the mixture are imposed.
The main steps of the glass batch preparation process are proportioning and mixing processes. Glass batch may include 7-10 granular and clump materials (sand, feldspar, alumina, dolomite, soda, sulphate, chalk, saltpetre, coal, glass scrap etc.), 1-2 fluid materials (water, black oil-fuel or heating oil) and microadditives (selenium, cobaltous oxide, denol etc.). Amount of the dose proportioned and fed to the mixer fluctuates for different materials from several grams to 2-3 tons. For this purpose two-speed modes of loading and unloading of the strain-measuring weighing batchers and different methods of weight measuring are used in order to keep exact proportioning.
The optimal time for mixing of glass batch components depends on the cyclogram of material feed into the mixer and mixing volume and for different types of mixers is from 1,5 to 3,5 minutes.
Microadditives are put into the mixer as a part of premixes (preliminary mixture with a filler), prepared in the automated proportioning-mixing complexes for small additives.
Increased quality of glass batch is also reached by means of preliminary treatment of the off-spec raw materials (crashing, drying, milling, sieving, optical and magnetic separation etc.).
Taking into account that glass batch production includes all main preparation processes of multicomponent mixtures from receiving of raw materials, their conveying, processing, storing on out to proportioning, mixing, conveying of the mixtures, it is advisable to consider the glass batch as a base mixture for system analysis and synthesis of the new equipment and processes which can be also used in production of dry mixtures for refractory applications, electrode products, building materials and other products in different branches of industry.