Experimental study on dephosphorization of braided high phosphorus hematite ore dressing
With the rapid development of China's national economy, the demand for steel is increasing iron. China's current iron ore self-sufficiency rate is 50% to 60%, iron ore resources will be seriously insufficient, unable to meet the steel industry's demand for raw materials. However, China has a high- phosphorus -like hematite with a reserve of several billion tons. Due to the high phosphorus, aluminum and silicon, the ore dressing is difficult and cannot be used, which seriously hinders the development of the steel industry and develops and utilizes high-phosphorus Hematite will be especially important. For this reason, a dephosphorization test study was carried out on a braided high-phosphorus hematite.
First, the nature of the ore
For the mineral technology study of a braided high-phosphorus hematite, the results of multi-element chemical analysis of ore are shown in Table 1.
Table 1 Results of multi-element chemical analysis of hematite
It can be seen from Table 1 that although the iron grade in the ore is 42.59%, the content of harmful elemental phosphorus is also high, reaching 0.87%.
The iron, phosphorus and other elements in the ore mainly exist as independent minerals, among which the iron mineral composition is more complicated, mainly hematite, followed by limonite, others have a small amount of siderite, magnetite, etc.; It is a collophanite; the gangue minerals are mainly quartz , chlorite and kaolinite, and other gangue minerals also have trace amounts of amorphous carbon, calcite and zircon .
(1) Hematite. It has a close relationship with chlorite, apatite, quartz and limonite. The hematite and chlorite layers form a concentric zone structure. The nucleus is mainly quartz, followed by hematite, limonite, chlorite, and phosphate rock. Sometimes, the above two minerals form the core of the granule in the form of aggregates, chlorite and chlorite. It is often embedded in the concentric annular zone of hematite and chlorite in the form of aggregates. In addition, it can also be seen that the hematite and quartz are closely connected, and are often embedded in concentric annular granules composed of hematite and chlorite.
(2) Phosphate rock mine. It is the most important phosphorus mineral in the ore. It is mainly irregularly embedded in other gangue mineral gaps or in the gaps of the helium-like hematite particles. The colloidal phosphate ore is closely related to the hematite embedding. Sometimes the collophanite is in the form of the core of the hematite hematite. Occasionally, the colloidal phosphate is in the form of an anthracene ring and the hematite interbed is a concentric ring structure. exist. In addition, there are many fine hematite inclusions in the colloidal phosphate particles, and this part of the hematite is also difficult to completely dissociate from the collophosphate monomers.
Second, the beneficiation test
The phosphorus-containing mineral in the braided high-phosphorus hematite is mainly colloidal phosphate rock, and the mine is subjected to reverse flotation dephosphorization-baking-magnetic separation process test.
(1) Trial of anti-flotation rough selection inhibitor
When the grinding fineness is -0.074mm, 89%, and the BK-420 collector is 375g/t, the test results of the crude BK-620 inhibitor are shown in Figure 1.
Figure 1 Results of rough selection of BK-620 inhibitors
â—†-iron grade; â– -iron recovery rate; â—‹-phosphorus recovery rate; â–²-phosphorus grade
It can be seen from Figure 1 that the amount of BK-620 inhibitor increased from 2000g/t to 4000g/t, and the phosphorus content in the concentrate decreased from 0.49% to 0.29%; the dosage of inhibitors continued to increase from 5000g/t to 6000g/t. The phosphorus content in the iron concentrate increased, and the phosphorus content in the concentrate increased from 0.29% to 0.39%. When the inhibitor dosage is 4000g/t, the phosphorus content of the concentrate reaches the lowest value and the phosphorus content is 0.29%. So choose BK-620
The dosage of the preparation was 4000 g/t.
(2) Anti-flotation rough selection collector dosage test
When the grinding fineness -0.074mm accounted for 89%, and the BK-620 inhibitor reverse flotation coarse selection amount was 4000g/t, the test results of the rough selection of BK-420 collector were shown in Fig. 2.
Figure 2 Results of rough selection of BK-420 collector
â—†-iron grade; â– -iron recovery rate; â—‹-phosphorus recovery rate; â–²-phosphorus grade
It can be seen from Figure 2 that the amount of BK-420 collector increased from 375g/t to 625g/t, and the phosphorus content in iron concentrate decreased from 0.33% to 0.23%, but the recovery rate of iron concentrate was also greatly reduced. 73.59% fell to 61.82%. Considering the recovery rate and phosphorus content of iron concentrate, the dosage of BK-420 collector was determined to be 375g/t.
(3) Anti-flotation selection of collectors
After determining the rough selection system, the selected BK-420 collector dosage test was carried out. The results are shown in Figure 3.
Figure 3 Selected BK-420 collector dosage test results
â—†-iron grade; â– -iron recovery rate; â—‹-phosphorus recovery rate; â–²-phosphorus grade
It can be seen from Figure 3 that when the amount of selective collector is 312g/t, the phosphorus content of the concentrate has been reduced to 0.21%, but the iron recovery rate of iron concentrate has dropped too much, considering the iron concentrate recovery rate and iron concentrate. The amount of phosphorus, the selected BK-420 collector is set at 250g / t.
(4) Grinding fineness test
After determining the rough selection and the selected dosage, the grinding fineness condition test is carried out. The results are shown in Figure 4.
Figure 4 Grinding fineness test results
â—†-iron grade; â– -iron recovery rate; â—‹-phosphorus recovery rate; â–²-phosphorus grade
It can be seen from Fig. 4 that when the grinding fineness is 85%-0.074 mm, the phosphorus content of the concentrate is 0.28%; when the grinding fineness is 89%-0.074 mm, the phosphorus content of the concentrate is 0.23%; grinding fineness When the ratio of -0.074mm is 97%, the phosphorus content of the concentrate is 0.22%, and the iron grade does not change much. Therefore, the dephosphorization grinding fineness is set to be 89%-0.074 mm.
(5) Anti-flotation full open circuit test
On the basis of the conditional test, the reverse flotation dephosphorization open circuit test was carried out according to the flow and conditions shown in Fig. 5. The test results are shown in Table 2.
Figure 5 Reverse flotation dephosphorization open circuit test procedure
Table 2 % of anti-flotation dephosphorization full open circuit test results
It can be seen from Table 2 that under the conditions of one rough selection, one selection, and one sweep, an iron concentrate containing 0.24% of phosphorus and 61.18% of iron recovery can be obtained.
(6) Dephosphorization flotation closed circuit test
On the basis of the open circuit test, a closed circuit test was carried out according to the flow of Fig. 6. The test results are shown in Table 3.
Figure 6 Reverse flotation dephosphorization closed circuit test procedure
Table 3 % of reverse flotation dephosphorization closed circuit test results
It can be seen from Table 3 that the reverse flotation dephosphorization closed-circuit test obtained an iron concentrate with an iron grade of 45.22%, a phosphorus content of 0.23%, and an iron recovery rate of 84.74%.
(7) Magnetization roasting temperature test
The magnetization roasting temperature test was carried out on the dephosphorized iron concentrate. The test procedure and test conditions are shown in Fig. 7. The test results are shown in Fig. 8.
Figure 7 Magnetization roasting test procedure
Figure 8 Magnetization roasting temperature test results
â—†-iron grade; â– -iron recovery rate; â–²-iron yield
As can be seen from Figure 8, magnetization roasting-magnetic separation can improve the concentrate grade, the temperature rises from 850 °C to 950 °C, the iron concentrate grade increases from 56.24% to 61.23%, but the iron concentrate recovery rate decreases from 87.99% to 68.40%. . Taken together, the choice of firing temperature under conditions 915 ℃ firing pulverized coal and the amount of test time test.
(8) Magnetization roasting time test
The magnetization roasting time test was carried out on the dephosphorized iron concentrate. The test results are shown in Fig. 9.
Figure 9 Magnetization roasting time test results
â—†One iron grade; â– -Iron recovery rate; â–²One iron yield
It can be seen from Fig. 9 that the roasting time is extended from 20 min to 60 min, the iron concentrate grade is increased from 56.43% to 60.02%, and the iron concentrate recovery rate is increased from 68.32% to 82.56%. For comprehensive consideration, the roasting time is 60 minutes.
(9) Test of the amount of magnetized roasting coal powder
The iron concentrate after dephosphorization was subjected to a magnetic baking roasting coal powder dosage test, and the test results are shown in Fig. 10.
Figure 10 Test results of magnetic baking roasting coal powder
â—†-iron grade; â– -iron recovery rate; â–²-iron yield
It can be seen from Fig. 10 that the ratio of coal powder is 100:15, and the iron concentrate grade is 60.02%, and the iron concentrate recovery rate is 82.96%.
(10) Process test
The anti-flotation dephosphorization of the ore is carried out. The iron concentrate after dephosphorization is selected to have a calcination temperature of 915 ° C, a calcination time of 60 min, a calcined ore: coal ratio of 100:15 as a calcination condition, and the calcined product is ground to 90%-0.038 mm. Perform magnetic separation. Then, a reverse flotation-baking-magnetic separation process test was carried out, and the results are shown in Table 4.
Table 4 Raw ore reverse flotation - roasting - magnetic separation test results %
It can be seen from Table 4 that the final iron concentrate yield is 48.98%, the iron concentrate grade is 60.09%, the iron recovery rate is 70.02%, the phosphorus content is 0.23%, the Al 2 O 3 is 6.24%, and the SiO 2 is 5.81%.
Third, the conclusion
The phosphorus-containing mineral in the braided high-phosphorus hematite is mainly colloidal phosphate. The reverse flotation dephosphorization-baking-magnetic separation process can obtain iron grade 60.09%, phosphorus content 0.23%, iron recovery rate 70.04%. The iron concentrate can provide a technical basis for the development of a high-phosphorus hematite in China.
Hammer Union,Hammer Union Fittings,Industrial Hose Coupling,Industrial Hose Connector
Hebei no one but god energy equipment co.,ltd , https://www.p-harcourtbrothers.com