Two-beam laser purification of quartz raw material

The paper presents a numerical simulation of laser separation under the influence of laser beams with wavelengths of 10.6 microns and 1.06 microns on quartz raw material used in the electronics industry in the manufacture of photomasks. The temperature fields obtained by the finite element method and the analytical solution are compared. The temperature distribution to a depth of 50 microns is almost the same when using both methods of solution, while with increasing depth the temperature difference increases by 10 %, which allows using both methods of solution, since in practice the temperature distribution in the near-surface layers, which determines the formation of agglomerates with impurity inclusions, is more important. It is revealed that the efficiency of separation of quartz raw material depends on the processing speed and the energy properties of laser radiation, which allows to choose the optimal processing parameters that ensure the effective formation of agglomerates containing impurity inclusions. Experimental studies of bi-beam laser cleaning of quartz raw material were carried out, which allowedus to determine the optimal processing parameters of quartz raw material for effective cleaning of it from impurity inclusions, that make it possible to manufacture photomasks used in the production of microcircuits with improved performance characteristics.

The process of obtaining quartz sand size fraction -0.4 + 0.05 mm for use in water glass production

The paper presents the process of quartz sand processing from the „Bijela Stijena“-Skočić deposit in the plant „Kesogradnja d.o.o.“ at Kozluk near Zvornik, Republic of Srpska. Bearing in mind the fact that this quartz sand is used for water glass production in the company „Birač“ - Zvornik or „Alumina“ Zvornik, it was necessary to meet the quality requirements prescribed by that industrial production. Thus, the required size was -0.4+0.05 mm and the Fe2O3 content was maximum of 0.04%. Based on the laboratory tests, a technological scheme for the quartz raw material valorization was conceived in the separation of the company „Kesogradnja d.o.o.“. The obtained results showed that quartz sand for water glass size fraction -0.4+0.05 mm could be obtained in the plant. Also, by introducing a magnetic concentration after washing and grading, the Fe2O3 content was reduced from 0.131% as it is in the initial sample to 0.038% which meets the required conditions from the water glass producers.

The choice of high gradient magnetic separation processes for removal of Fe2O3 carriers from quartz raw material

This review article surveys the subject of choice of high gradient magnetic separation processes for removal of Fe2O3 carriers from quartz raw material by electromagnetic separator with magnetic field intensity of 1.4 T.