An investigation into application of calcination and briquetting to-3 mm tailing of Emet-colemanite concentrator plant

Some of the main problems Borate Industries faces are higher holding costs and serious environmental hazards caused by borate tailing. The goal of this research study is to produce a saleable borate product from the -3mm tailings of Emet-Espey Concentrator Plant. By solving this problem, it will contribute significantly to our countries economy. In experimental studies, it has been observed that the tailings samples contained % 19.2 B2O3 and significant amount of Arsenic (As) and Fe2O3. Decrepitation method is used to recover the B2O3 contents of the samples. After processing the very finely sized colemanite concentrates by calcinations, the samples were briquetted to obtain the saleable products. By applying the decrepitation tests, a calcined colemanite concentrate containing % 35.64 B2O3 and 700 ppm Arsenic at a recovery of % 53.91 B2O3 and removal rate of % 92.58 Arsenic were produced of 850°C in 60 minute tests from the -1.18 +0.5 mm size samples. For the -0.5 +0.212 mm size samples, a concentrate containing % 36.07 B2O3 and 1610 ppm Arsenic were produced at a recovery of % 56.86 B2O3 and removal rate of % 82.67 Arsenic at 850°C in the 60 minute tests. For the -1.18 +0.5 mm and -0.5 +0.212 mm size samples, they were added to test together by briquetting since their grades were very close each other. The grade of calcined colemanite samples which are briquetted are % 35.87 B2O3 and sized under 0.212 mm. Optimum parameters of briquetting tests were obtained as samples weight of 20 gr, % 30.28 boric acid, % 25 moisture and 6 kN compressive stress. In these conditions, the average compressive strengths of briquette samples with a grade of % 43 B2O3 were measured as 6.815 N/mm2. From the results of laboratory-scale decrepitation tests on the tailings of-3mm sized, Emet-Espey Concentrator Plant, saleable products with % 43 B2O3 content with 30mm diameter and 30 mm height can be obtained by briquetting method. Additionally, less environmental hazards will be caused by decrepitation because of dry processing. Keywords: Borate Tailings, Decrepitation, Calcinations, Briquetting, Tailing Evaluation.