Kompleks Sülfürlü Bir Cevherde Doğal Yüzebilir Silikatların Bastırılması
Özet
In flotation enrichment, many of the host rocks that can be found in the ore structure can make the enrichment process quite difficult. Within the scope of this thesis, it has been tried to produce salable copper and zinc concentrates from a complex sulfide ore in Balıkesir region in Turkey by flotation method. However, talc mineral, which can be found as a host rock in the ore, is an unwanted naturally floating silicate mineral during copper flotation. Minerals such as talc and chloride remained in the copper concentrate during flotation, reducing the copper concentrate grade, causing penalties at the smelting stage, troubles during the pyrometallurgical processes, and an increase in the cost during the ore shipment stage. Therefore, it is very important to suppress or remove talc and natural floating silicates from the system.
Within the scope of the thesis study, 2 different methods were compared with each other in order to eliminate this negative effect of talc on copper concentrate. The first method is to remove the floating gangue minerals from the system by pre-float, and the second method is to prevent these minerals from reaching the final concentrate by depressing. These naturally hydrophobic minerals which are very difficult to depress. Today, organic depressants are used to depress these minerals. Within the scope of this thesis, natural floating silicates were tried to be depressed by using an organic depressant, CMC (Carboxymethyl cellulose). Three different types of CMC and three different dosages were used in the study to depress talc.
The condition of direct flotation of copper without depressing the talc with pre-aeration was accepted as the standard flotation condition for the studied ore. The CMC that gave the best results in the experiments was determined as the CMC named 30G. In addition, in order to determine the effects on the system in case of recycling the flotation wastewater, synthetic plant water was prepared in the optimum conditions obtained and closed circuit flotation tests were carried out in which the tailing water was recycled to the mill stage 3 times.
In the recirculating closed-circuit water tests made with synthetic plant water prepared in pre-flotation condition, the collectors that are not absorbed and accumulated in the system also float the copper minerals in the pre-float stage where talc is intended to be removed from the system by floating, reducing the final recovery and causing copper loss. As a result of pre-float tests, 29.37% final copper concentrate with an average recovery of 51.92% was obtained in the copper circuit, and final zinc concentrate with a grade of 47.14% with a recovery of 67.24% was obtained in the Zn circuit. However, in the second method, in which talc is depressed with CMC, as a result of the recirculating closed circuit water flotation tests, the final copper concentrate with an average grade of 29.22% final copper concentrate with an average recovery of 74.12% was obtained in the copper circuit, and final zinc concentrate with a grade of 50.58% with a recovery of 71.27 % was obtained in the Zn circuit.
As a result, depression of talc minerals with CMC gives a much better flotation performance compared to removing these minerals from the system by pre-flotation. Although successful results can be obtained with pre-flotation in such problematic ores in the first flotation stage, especially in today's issue of water shortage is increasing, when the negative effects of reversing the wastewater and the reagents remaining in the water are considered, it was concluded that depression of floating silicates is a more effective and economic solution.
