Investigation on the effect of calcium sulphate based boron waste in gypsum

In this study, the usability of the Kütahya-Emet boric acid factory, boron processing industry during production, process waste containing CaSO42H2O, which creates storage and environmental problems in its structure, was investigated. Mineralogical, thermal and chemical properties of waste have been studied. The process of calcination at constant temperature (120 oC) and at different times (12 and 24 hours) has determined the conversion of waste hemihidrat to structure. The effects of the samples added to the plaster with increased rates of untreated and calcined wastes on mechanical, physical and workability properties were evaluated. Citric acid, malic acid and tartaric acid were used as auxiliary additives to slow the hydration rate of partial calcined waste. The effects of these contributions were determined with the addition. With the addition of untreated and partial calcined waste, it has been observed that the workability of the witnessing plaster is reduced in bulk density and strength. In the studies, citric acid and malic acid workability as auxiliary additives has a positive effect, but it has a negative effect on mechanical and physical properties. As a result of these studies, it was determined that the workability values of the witnessing plaster can be reached using the addition of tartaric acid. Thus, it has been concluded that the waste can be used on the condition that tartaric acid additives are added within the witness plaster.