This article investigates the effect of attrition of fine waste coal from anthracite mine “Vrška Čuka, Serbia on the flotation results and flotation kinetic parameters in a batch flotation cell. Waste coal was generally stored into settling ponds and old tailing ponds as a waste material. Floatability of oxidized coal can be improved by attrition. The flotation tests were performed with and without attrition using different dosages of kerosene. The best results were observed on the waste coal combined flotation with attrition (attrition time 10 minutes) using 5,000 g/t kerosene. These results are compared with obtained coal recovery of raw coal. Based on batch flotation test data of the coal, the nonlinear fitting was conducted using a MatLab tool for modeling the first-order flotation kinetics. The cumulative combustible recovery against flotation time were correlated using the classical model and modified Kelsall model. The attrition had a positive effect on the coal flotation kinetics parameters. Also, both models showed good correlation; however, the modified Kelsall model provided the best fit.

Thionocarbamates are the group of collectors that are mostly used for flotation of sulphide copper minerals, alone or in combination with xanthates depending on a mineralogical composition of the ore. In this paper, the results of the study of application of thionocarbamates in copper slag flotation are presented. Chemical analysis of smelter slag sample obtained from Flotation plant in Bor, Serbia, showed that it contains 3.56% of copper, of which over 73% is in the sulphide form, as well as 0.58 g/t of gold and 11.30 g/t of silver. XRD analysis identified fayalite and magnetite as main minerals present in the slag and SEM-EDS analysis showed that copper is mainly present in the form of sulphide minerals, thus making it suitable for flotation with thionocarbamates. Two thionocarbamates MX 980 and TC 1000 and one xanthate SIPX, along with their mixtures MX 980 + SIPX and TC 1000 + SIPX, were investigated. The influence of parameters such as collector type and dosage, grinding fineness, pulps’ pH and flotation time, on flotation indicators (recovery, yield and copper grade in concentrate) were determined. Smaller dosages of thionocarbamates (40 g/t) provided concentrates with high copper grades, 22.34% (MX 980) and 18.42% (TC 1000) and lower recovery rates, 83.98% (MX 980) and 87.78% (TC 1000), while the increase of dosages to 200 g/t led to the increase of recovery rates for more than 4% and a significant decrease in copper grades. The increase of grinding fineness from 50% to 70% of grain size < 0.074 mm showed a positive impact on flotation indicators, recovery rate, copper grade and yield, for all investigated collectors and their mixtures, while, with the further increase from 70% to 90%, recovery rates continued to increase while copper grades decreased. The increase of pulps’ pH had a positive influence, especially for MX 980, for which recovery rates increased with the increase of pH from 8 to 10 (12). A flotation kinetics test showed that flotation with TC 1000 was the fastest, i.e., recovery rate after 20 min of flotation was over 91%, while recoveries obtained with other collectors were a few percentage points lower.

In this study the effect of mixtures of copper slag and flotation tailings from copper mine Bor, Serbia on the flotation results of copper recovery and flotation kinetics parameters in a batch flotation cell has been investigated. By simultaneous adding old flotation tailings in the ball mill at the rate of 9%, it is possible to increase copper recovery for about 20%. These results are compared with obtained copper recovery of pure copper slag. The results of batch flotation test were fitted by MatLab software for modeling the first-order flotation kinetics in order to determine kinetics parameters and define an optimal model of the flotation kinetics. Six kinetic models are tested on the batch flotation copper recovery against flotation time. All models showed good correlation, however the modified Kelsall model provided the best fit.

This paper presents the results of mineralogical and flotation studies on the copper ore from the deposit "North Revir" in the Copper Mine Majdanpek, using different collectors. XRD and ore mineralogical analysis showed that the most common minerals are pyrite and chalcopyrite. Chemical analysis confirm that it is a complex low-grade copper ore with average copper content of 0,273%. The content of precious metals (Au and Ag) was 0.2 g/t and 1.2 g/t, respectively. The main aim of flotation studies have been the effect of collector type on the recovery and concentrate grade in the copper flotation process. Various collectors and combinations of them were used in the rough flotation tests of copper ore. The copper recovery was in the range from 79.43% (test no. 4) to 84.96% (test no. 7). The best flotation results were obtained with mixture collectors of sodium isopropyl xanthate (Z11), dialkyl dithiophosphinates (Aerophine 3404) and SKIK BZ 2000. The collector's dosages of 20 g/t Z11, 8 g/t AP3404 and 8 g/t SKIK BZ 2000 produced the copper recovery (84.96 %) with copper concentrate grade of 1.52% .