Microalgae are rich in inorganic compounds and can grow rapidly, thereby producing valuable byproducts in various fields, such as pharmaceutical and food industrials. At the end of the growth phase of the microalgae, one of the problems that exist in harvesting the biomass is lack of a suitable machine for the isolation of microalgae from culture with low-cost is not available. In this study, the Electro-coagulation- FLOTATION method was used to harvest Chlorella sp. from the culture medium, the impact of three parameters, current, electrolytes and duration of the process was evaluated for its efficiency. The results show that the run time has the greatest impact in harvesting, so that the highest recovery efficiency was attained in the longest time. On the other hand the increase in currency speeds up the clotting and harvesting of the microalgae; but the energy consumption is high. The highest efficiency of biomass harvesting was obtained 88.3 % with a currency of 16 mA.cm-2 and duration of 30 minutes.

The effects of surface dissolution by oxalic acid were investigated on the FLOTATION kinetics and kinetics of collector adsorption in ilmenite FLOTATION in the presence of olivine-pyroxene, tremolite-clinochlore and quartz. Fitting of first order kinetic model on the results of FLOTATION before and after surface dissolution showed that FLOTATION kinetic constant (K) and ultimate recovery (R∞, ) of ilmenite is increased after surface dissolution and they are decreased for gangue minerals. The results showed that kinetic selectivity index of ilmenite in the presence of olivine-pyroxene, tremolite-clinochlore and quartz are increased from 1. 28 to 1. 98, 1. 42 to 3. 02 and 3. 58, respectively, after surface dissolution indicating the positive effect of surface dissolution process. Investigating the kinetics of collector adsorption showed that the collector adsorption is conforming to second order kinetic model. After surface dissolution, the kinetics of collector adsorption and initial rate of collector adsorption on ilmenite surface is increased from 3. 85 to 8. 44 g. mol-1 min-1 and it is decreased for olivine-pyroxene, tremolite-clinochlore and quartz from 6. 33 to 5. 03, 7. 3 to 6. 22 and 7. 77 to 7. 37 g. mol-1 min-1, respectively. These results are in good agreements with the results of collector adsorption via UV analysis which the collector adsorption on ilmenite surface is increased and it is decreased for gangue minerals after surface dissolution. The results of SEM showed that the surface of ilmenite becomes smoother and uniform and about the gangue minerals, some cavities are produced due to dissolution of surface cations.

During the FLOTATION operation, recovery may increase, decrease or remain constant with variation of parameters like pH, type and concentration of collector, type and concentration of depressant, % solid in pulp and many others. In this study the attempts have been made to use the FLOTATION rate data to optimize the above parameters and on account of this, the optimum RTD for such model has been determined. In order to control, evaluate and select the suitable parameter, the separation optimized conditions: PH: 9                                                                                                                                         Depressant: 1000 (g/t)                                                                                                                r.p.m:1000                                                                                                                                 %Solid: 23 Time of d80 = 75: 14 minIt is possible to achieve S.E = 87%  

Molybdenite FLOTATION in the Sarcheshmeh Copper Complex was studied as a function of pulp potential, controlled using two types of sodium sulfide, a mineral origin and a chemical nature. Air and either plant or laboratory nitrogen were used as FLOTATION careers. Potential readings took place in rougher cells, as it was proved to be vital in the molybdenite circuit. Results showed that, at reducing potentials between -525 and -575 mv, the highest molybdenum recovery of 93% and the lowest copper recovery of 4-15% can be achieved. These potentials did not change considerably by adding extra amounts of sodium sulfide. At more oxidizing potentials, i.e. more than -450 mv, copper recovery increases while the recovery of Molybdenite drops.

FLOTATION is the most important process for concentrating mineral ores. This process may occur in any vessel such as column FLOTATION, which has been used widely during the last decade and the conventional FLOTATION cells. The effect of superficial feed velocity on the copper recovery was investigated using pilot-scale column FLOTATION of "Sarcheshmeh Copper Complex". The results were compared with the conventional FLOTATION cell data. It was reveled that for coarse particles (d(80)=90 mu m) this column could not be used instead of cells and rougher cells, but for small particles (d(80)=44 mu m) it could, For coarse particles, recovery curve demonstrated a maximum with increase in feed rate. However a minimum was observed for fine particles.

In this paper, we report a geospatial assessment of the selected mine sites in the Plateau State, Nigeria. The aim of this work is to determine the impact of mining on the terrain as well as the Land Use/Land Cover (LULC) of the host communities. The Shuttle Radar Topographic Mission (SRTM) is used for the terrain mapping. The derived impact of mining on LULC between 1975 and 2014 is determined by classifying the relevant Landsat imageries. The digital terrain map reveal that the mining activity is not well-coordinated. Hence, the parts of the mine sites that are rich in the desired minerals are punctuated with low depth, while the other parts have high terrain as a result of the haphazard mining activity. The analysis of the LULC change show that the degraded land (DL), built-up area (BU), water bodies (WB), and exposed rock outcrop (RO) increase by 15. 68%, 4. 68%, 0. 06%, and 14. 5%, respectively, whereas the arable farmland (FL) and forest reserve (FR) decrease by 28. 29% and 6. 63%, respectively. Mining has adversely affected the natural ecology of the studied area. Therefore, the mine sites should be monitored, and their environmental damages should be pre-determined and mitigated. There should be regular inspections to keep these activities under control. The existing laws and regulations to conserve the natural ecosystems of the host communities should be enforced to curtail the excesses of the operators of the mining industries. Restoration of the minefields to reduce the existing hazards prevent further environmental degradation, and facilitating the socio-economic development of the area is also suggested.

Removal of carbonate impurities in sedimentary phosphate is one of the most important issues in the industry. Poor selective FLOTATION of those ores is due to the similarity of Physico-chemical surface properties, solubility, and electrokinetic characteristics of sparingly soluble phosphate and carbonate minerals. In this study the effect of ultrasonic irradiation as a pretreatment method on reverse FLOTATION of low-grade sedimentary phosphate sample from Lar Mountain deposit was investigated. Ultrasonic was utilized before FLOTATION at different ultrasound intensity. This study was performed by two FLOTATION approaches; i) using experimental design (Plackett-Burman method with 11 variables), and ii) try and error method. Initial mineralogical studies showed that the feed sample contains 10. 34%P2O5, 48. 01%CaO, and 9. 22%SiO2. The collected data from experimental design were analyzed by DX7. 0 software to assess the influence of each parameter on FLOTATION performance. The results indicated that ultrasound intensity, collector dosage, and dispersant dosage were the effective parameters. The results of the try and error method showed that the conditioning time was the most effective parameter in which by reducing ultrasonic preparation time the recovery was increased relative to 33. 29%. Finally, the kinetic FLOTATION tests and SEM studies were performed. The results proved surface cleaning of phosphate minerals which treated by ultrasound irradiation that led to better adsorption of chemicals which increased the recovery and grade of P2O5 for 87. 88% and 14. 45%, respectively. However, the application of the ultrasonic treatment reduced the FLOTATION chemicals’ consumption which is a prominent issue for phosphate treatment.