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Fig. 6 Flow sheet of the classification, gravity, and flotation combination processes for upgrading the phosphate fines

Figure 6 Flow sheet of the classification, gravity, and flotation combination processes for upgrading the phosphate fines

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Table 2. Chemical and size analysis of the Cyclosizer However, in the pre-concentration stage, classification and gravity combination processes will ensure tailings to be sepa- rated from the valuable material, thereby achieving a 94.92% POs recovery.
Table 2. Chemical and size analysis of the Cyclosizer However, in the pre-concentration stage, classification and gravity combination processes will ensure tailings to be sepa- rated from the valuable material, thereby achieving a 94.92% POs recovery.
Table 1 Chemical analysis of the — 45-t1m fraction LR. insoluble residue, L.O.L. loss on ignition 2.2.2 Classification
Table 1 Chemical analysis of the — 45-t1m fraction LR. insoluble residue, L.O.L. loss on ignition 2.2.2 Classification
POs recovery and MgO% of the phosphate concentrate (sink fraction) were measured as a function of enzyme dosage using
POs recovery and MgO% of the phosphate concentrate (sink fraction) were measured as a function of enzyme dosage using
Table 3 The results of the Falcon for the separation of silica from phosphate fines 3 Results and Discussion 2.2.4 Bench Scale Flotation
Table 3 The results of the Falcon for the separation of silica from phosphate fines 3 Results and Discussion 2.2.4 Bench Scale Flotation
using cellulase enzyme as a new depressant for phosphate [19]. A probable mechanism of oleic acid and enzyme interaction on the mineral surface was suggested (Fig. 3). This mechanism explained this new finding according to t he hydropho between the hydrocarbon chain of oleic acid (adsorbed eral surface) and the hydrophobic pocket surface. The created new surface became presence of hydrophilic groups on t hydrophilic d he enzyme Apparently, this occurred on the phosphate mineral and not on the dolomite surfaces. In suc bic bond on min- found on the enzyme ue to the surface. surfaces h case, the p hosphate mineral was reported to the sink fraction since the enzyme tended to be the depressant for phosphate, while carbonate 5-10 * mol/dm” oleic acid as a collector. Results are shown in Fig. 3. The results indicate that enzyme is a strong depressant, for phosphate-containing mineral, when enzyme dose exceeds 0.1%. The addition of enzyme increased P.O; and decreased MgO content of the concentrate. The recovery of POs; in the concentrate increased from 12.76 to 64.82%, and that of MgO decreased from 1.46 to 0.61%. On the other hand, the grade of MgO in the tail (floated fraction) increased from 1.46 to 2.68%. These results indicated that the enzyme is a depressing agen for phosphate-containing mineral whereas the carbonates were not affected. However, this was a direct application of one of the authors’ findings during the oleate flotation of phosphate
using cellulase enzyme as a new depressant for phosphate [19]. A probable mechanism of oleic acid and enzyme interaction on the mineral surface was suggested (Fig. 3). This mechanism explained this new finding according to t he hydropho between the hydrocarbon chain of oleic acid (adsorbed eral surface) and the hydrophobic pocket surface. The created new surface became presence of hydrophilic groups on t hydrophilic d he enzyme Apparently, this occurred on the phosphate mineral and not on the dolomite surfaces. In suc bic bond on min- found on the enzyme ue to the surface. surfaces h case, the p hosphate mineral was reported to the sink fraction since the enzyme tended to be the depressant for phosphate, while carbonate 5-10 * mol/dm” oleic acid as a collector. Results are shown in Fig. 3. The results indicate that enzyme is a strong depressant, for phosphate-containing mineral, when enzyme dose exceeds 0.1%. The addition of enzyme increased P.O; and decreased MgO content of the concentrate. The recovery of POs; in the concentrate increased from 12.76 to 64.82%, and that of MgO decreased from 1.46 to 0.61%. On the other hand, the grade of MgO in the tail (floated fraction) increased from 1.46 to 2.68%. These results indicated that the enzyme is a depressing agen for phosphate-containing mineral whereas the carbonates were not affected. However, this was a direct application of one of the authors’ findings during the oleate flotation of phosphate
3.3 Effect of Temperature The activities of enzymes are affected by temperature [21-24]. However, heat may affect enzymes in two ways [26]. One effect is inactivation since high temperatures cause denaturation of the enzyme protein resulting in a loss of catalytic properties. The second effect of temperature on en- zymatic reactions is in their rate. Like most chemical reac- tions, enzyme-catalyzed changes are increased in rate by rais- ing the temperature. However, with an enzyme reaction as temperature is increased, thermal inactivation of the enzyme may take place so rapidly as to more than offset increased rate of reaction due to the higher temperature. Figure 5 presents the results of heating the pulp on enzyme activity. In these series of experiments, the conditioning pH was 9 using 5-10 * mol/ dm? oleic acid as a collector and a lower enzyme dosage of 0.1%. Using this low concentration of enzyme, it is noticed that at temperatures of 30 °C and 40 °C, there is an activation effect of enzyme on flotation separation. The highest activity of enzyme was noticed at a temperature of 25 °C. At this
3.3 Effect of Temperature The activities of enzymes are affected by temperature [21-24]. However, heat may affect enzymes in two ways [26]. One effect is inactivation since high temperatures cause denaturation of the enzyme protein resulting in a loss of catalytic properties. The second effect of temperature on en- zymatic reactions is in their rate. Like most chemical reac- tions, enzyme-catalyzed changes are increased in rate by rais- ing the temperature. However, with an enzyme reaction as temperature is increased, thermal inactivation of the enzyme may take place so rapidly as to more than offset increased rate of reaction due to the higher temperature. Figure 5 presents the results of heating the pulp on enzyme activity. In these series of experiments, the conditioning pH was 9 using 5-10 * mol/ dm? oleic acid as a collector and a lower enzyme dosage of 0.1%. Using this low concentration of enzyme, it is noticed that at temperatures of 30 °C and 40 °C, there is an activation effect of enzyme on flotation separation. The highest activity of enzyme was noticed at a temperature of 25 °C. At this
4 Conclusions Table 4 Results of the flotation separation at the optimum conditions Conditions: 0.1% enzyme, 5-10 * mol/dm? oleic acid, temp. 30 °C
4 Conclusions Table 4 Results of the flotation separation at the optimum conditions Conditions: 0.1% enzyme, 5-10 * mol/dm? oleic acid, temp. 30 °C
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