Bulut et al. (2011) investigated the depression effect of starch on pyrite flotation and found that starch was effective at a low dosage (1.7 mg L −1) and more pronounced at alkaline pH (10) than natural pH (6.5). This confirms the adsorption of starch on mineral surfaces through the interaction with metal-hydroxylated species.Web

The solution chemical analysis and micro-flotation experiments indicated that the Cu 2+ ions have produced copper hydroxide (Cu(OH) 2) precipitation under …Web

The flotation is optimum in the narrow pH range of 5.5 to 6, falls sharply at pH 5, and is moderate in the pH range 7 to 11, Infrared spectra indicate that copper …Web

Just prior to use, 1 g of chalcopyrite was ground in a small amount of "pretreated" water with a ceramic mortar and pestle. The mineral dispersion was then transferred into a water-jacketed, closed reaction vessel and conditioned at 21±0.2°C for 20 min. in 0.5 dm 3 of a 0.01 mol dm −3 KCl solution in the presence of nitrogen or oxygen …Web

In this paper, the effect of sodium butyl xanthate (NaBX) adsorption on the surface of bornite at different pH on flotation was studied by adsorption kinetic and thermodynamic. The flotation results demonstrated that the recovery was the highest when pH was 9 in NaBX solution (4×10−5 mol/L). The adsorption kinetics showed the reaction …Web

that make the flotation process more difficult. The diameter of the characteristic minerals – chalcosine, covellin, bornite in the copper sulfide ore varies: 0.2 mm for chalcosine and to 0.03 µm for bornite. The chalcocite inclusions have equigranular structure [1]. Theoretical substantiations and experimentally confirmed optimal conditions forWeb

The results showed an improvement in flotation and flocculation performance when tests were carried out with treated seawater at pH > 10.5, where the copper recovery increased from 82% to 95% ...Web

Porphyry copper deposits are important sources of copper and typically processed by flotation to produce copper concentrates. As mining areas become deeper, the amounts of impurities, such as sphalerite, can be increased in copper ores, so the appropriate depression of sphalerite floatability should be achieved to obtain saleable copper …Web

An increase in degree of bornite surface oxidation to a magnitude of 7.48, induced by a H 2 O 2 concentration of 2 wt%, led to a dramatic decline in flotation …Web

Chalcopyrite, CuFeS 2, is an important source of copper and is recovered from ore by the flotation process.Chalcopyrite is commonly associated with other metal sulfides, e.g. bornite, Cu 5 FeS 4.In this study the effect of bornite on the oxidation and leaching of chalcopyrite has been investigated by probing the surface evolution of pure …Web

The Denver cell test with a porphyry ore shows a selective flotation with IPETC at a pH of 11 with a low collector dosage (5 g/ton), achieving recoveries of 92% covellite and 39% pyrite. Also, recoveries of 85% covellite and 75% pyrite were observed for a bulk flotation with IPETC at pH = 8 at the same collector dosage.Web

148 ii. Surface colloid and reagent chemistry which determines selectivity of separation (collectors, frothers, Process …Web

The four flotation concentrates were combined and reground in a rod mill with stainless steel grinding media. The total weight of grinding media was about 10.3 kg.Particle size P 80 = 20 μm was achieved by adjusting the grinding time. The size distribution was determined by Laser Diffraction with a Malvern MasterSizer (Malvern Instrument Ltd., …Web

Abstract—This study investigated the effect of pH on the recovery and grade of the Platinum Group Metals (PGMs) and base metal sulphides from the UG2 ore of the bushveld complex. This was achieved through running a series of test work in a Denver flotation cell at varying pH 6-11 at constant reagent dosage. The UG-2 reef is characterized by twoWeb

The solution pH of single bornite substantially increased from 1.7 to 4.6 in the first 11 days, after that pH maintained at approximate 4.6. Conversely, the solution pH of single pyrite decreased continuously. Trends of pH suggested that the dissolution of bornite was an acid consuming process, while the dissolution of pyrite was an acid ...Web

Interactions between chalcopyrite and bornite during bioleaching by moderately thermophilic bacteria were investigated mainly by X-ray diffraction, scanning electron microscopy, and electrochemical measurements performed in conjunction with bioleaching experiments. The results showed that a synergistic effect existed between …Web

1.1. Effect of pH on Flotation pH control can be used to selectively float specific ores in a mineral mixture. This may be of particular importance in complex separations such as in the case of bornite and chalcocite. This is due to the ore itself either exhibiting alkaline or acidic properties, whichWeb

The process is commonly carried out in alkaline pH adjusted with lime to depress pyrite, but in seawater depressing effect of Ca ions on molybdenite flotation is augmented, and different pyrite ...Web

In the flotation process a number of physicochemical variables are important. According to- [6], the important physico-chemical variables in flotation are: i. Role of mineral/water interface. ii. Surface charge on the minerals. iii. Effect of hydrocarbon length of the collector. iv. Effect of neutral molecules. v.Web

Flotation of chalcocite and bornite in a mi xed mineral system resulted in higher copper recovery compared to the weighted sum recoveries of the individual minerals. This ... 6.2 Effect of pH on the surface charge of bornite and chalcocite ..... 62 6.3 Changes in surface charge of bornite and chalcocite in the presence of other ...Web

The Hallimond flotation results presented in Figure 6 confirm that it is possible to float the sulfides at the natural pH region, since the recovery of chalcopyrite is highest at pH 7, and that of chalcocite and bornite at pH 8. It is also notable that while the recovery of chalcocite and bornite is very low at acidic pH, recovery of ...Web

The Importance of pH in Flotation In flotation, pH control is a vital method to control selective mineral separation. A standard …Web

The effect of flotation operational parameters on froth stability and froth recovery was studied. Froth stability was measured using a special column. To determine the froth recovery, the froth height change model and froth …Web

The addition of Ca (ClO)2 at pH 8.7 enhances pyrite hydrophilicity and decreases flotation recovery by ∼60%. Solubility tests and Visual MINTEQ model analysis indicate that Ca (ClO)2 promotes ...Web

Fig. 2 shows chalcopyrite flotation recovery in the pure water, sea water and 0.05 M MgCl 2 solutions at pH 10. The cumulative recovery was approximately 70% in pure water after 10 min, indicating a good natural floatability of chalcopyrite. An apparently lower chalcopyrite recovery of 58% was observed in sea water, especially in the initial stage, …Web

3 rowsAbstract: In this paper, the effect of sodium butyl xanthate (NaBX) adsorption on the surface of ...Web

When considering Table 3, it is clear that the majority of conditions used in this study would promote the flotation of chalcocite as shown by the ratios being less than one in most cases. pH 5 in DIW shows a particularly high preference for bornite flotation, while pH 3 in DIW and pH 7 in SPW show a higher preference for chalcocite flotation ...Web

The major sulphide minerals were chalcopyrite, sphalerite, pyrite, chalcocite and bornite. The liberation size for flotation feed was 80% passing 38 μm. In addition to the existing condition, two more sampling surveys were performed at steady-state condition around the Zn rougher bank in a Cu–Zn flotation plant at two different collector ...Web

Figure 14: Collectorless flotation of pyrite in the presence of Cu2+ ions (pH 9.2, flotation time - 5 min). [15]. ..... 28 Figure 15: Effect of atmosphere (grinding, flotation) on chalcopyrite floatability after grindingWeb

The wettability and floatability of oxidized chalcocite, bornite, and chalcopyrite with the conditions of sodium hydrosulfide (NaHS) dosages and pHs were studied by contact angle measurements, and single and mixture mineral flotation tests. To evaluate the results of the flotation, the flotation kinetic model for copper sulfide …Web

Although flotation studies of bornite under oxidation treatment are spares in the literature, bornite oxidation is much faster than chalcopyrite but slower than that enargite and tennantite (Acres ...Web

The bornite and chalcopyrite results indicated that Fe 2 O 3 was produced on bornite surfaces with an increase in pH, whereas the chalcopyrite surfaces were covered as the pH decreased. A flotation test was conducted using a Chilean copper ore that contained chalcocite, bornite, and chalcopyrite, and the flotation recovery of each …Web

Effect of oxidation treatment using hydrogen peroxide (H 2 O 2) on the floatability of copper sulfide minerals (i.e., chalcopyrite and bornite) and arsenic-bearing copper minerals (i.e., tennantite and enargite) is reported in this study.Pure mineral flotation shows that the floatability of each mineral significantly decreases after the oxidation …Web