STUDY OF THE EFFECT OF FLOCCULANT TYPE, FLOCCULANT DOSAGE AND SLURRY SOLIDS PERCENTAGE ON DEWATERING PROCESS OF GOLD PROCESSING TAILINGS

• Main Author: Sylvastro Sacchie Lende, Nigel
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/74847
• Institution: Institut Teknologi Bandung

Gold is one of the most valuable metals due to its limited availability and special properties. Gold in nature can be found as a mineral or impurity contained in sulfides. Gold found today is generally in complex ores where the concentration of gold is lower and as fine-sized inclusions. Processing complex ores requires grinding to an ultra-fine size so that the gold particles can be physically freed from other particles so that they can then be extracted. Fine particle sizes will be effectively treated by wet methods resulting in slurry tailings. This tailings condition is unsafe and carries the risk of possible particle segregation making the tailings storage facility (TSF) unstable. Fine particles are stable in a suspended state and require an exceptionally long time to separate from water naturally. Dewatering can shorten the separation time, reducing the risk and improving the stability of the TSF. Increased social awareness as well as stringent government regulations make tailings management planning even more important. Therefore, this research, which explores and discusses the dewatering process of tailings slurries with several types of flocculants, is important in order to serve as a reference in the planning stage of tailings management. A series of experiments were conducted to study the dewatering process of gold processing tailings slurry from PT Agincourt Resources using various flocculants as reagents obtained from PT SNF Florindo. Samples were prepared for characterization and testing. Flocculant selection was carried out to obtain flocculants that could provide the best flocculation performance from conventional flocculant, terpolymer flocculant and acrylamide tertiary-butyl sulfonic acid flocculant. All selected flocculants were then used in all tests conducted consisting of pouring test, drainage test, slump test and settling test. Pouring tests were conducted to study flocculation while drainage tests and slump tests studied the application of flocculation to the filtration process and settling tests studied the application of flocculation to the sedimentation process of the tailings slurry. Flocculant selection provides flocculants that are able to form large flocs using low doses for conditions of 50% solids, namely Dryfloc 34 E of conventional flocculant type at 220 grams/ton, Dryfloc 5220 E of terpolymer flocculant type at 140 grams/ton and Dryfloc SU 25 E of acrylamide tertiary-butyl sulfonic acid flocculant type at 120 grams/ton. The best flocculation process was obtained using Dryfloc SU 25 E under conditions of percent solids of the tailings slurry sample of 40% and a dose of flocculant of 120 grams/ton. The use of Dryfloc 34 E with a dose of 240 grams/ton at 50% percent solids of the tailings slurry sample provides the fastest filtration process. While the shortest sedimentation period was achieved when adding Dryfloc with a dose of 160 grams/ton 5220 E under conditions of percent solids of the tailings slurry sample of 20%. Higher flocculant doses can provide better dewatering results because there are more locations to bind and charge for destabilization, but excessive doses can cause restabilization of solid particles in suspension. Increasing the percent solids of the tailings slurry can result in a better dewatering process because flocculant interactions are easier to occur, but too high a percent solid can have the opposite result due to a shift in the mechanism towards hindered settling.