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Regarding the "dry selection and tailing", it can be considered, but the tailing effect and the location of the tailing are to be verified. Because the work is placed in front of the ball mill , the moisture content in the ore is large during the rainy season. If the ore is fine, the "magnet" will be generated, which will affect the tailing effect. 
I. Introduction
Commissioned by XXXX, Xian Zhou Mining Technology Development Co., Ltd. in November 2008, Jiangsu XXXX top iron ore ore optional test, its purpose is optional through experimental study of ore, that type Iron ore provides a set of economical and technically feasible processes to provide a scientific basis for the development and utilization of the iron ore.
In the course of the test, the detailed mineralogical study of the iron ore was first carried out, including semi-quantitative analysis of the original ore spectrum, multi-element analysis of the original ore, iron ore phase analysis and ore X-ray diffraction analysis. The types and occurrence characteristics of ore minerals and the structural characteristics of the ore were identified. The particle size distribution and embedding relationship of the iron minerals were ascertained, and the types, particle size distribution and embedding relationship of the gangue minerals were ascertained. The researchers have a clear understanding of the iron ore research, and played a guiding role in the preparation of iron ore process and test conditions.
The iron ore, as determined by ore process mineralogical studies, has a relatively simple phase composition of ore samples, such as magnetite, hematite, limonite and trace pyrite. The structure of the ore mineral is simple and the ore undergoes slight oxidation and fragmentation. Therefore, the particle size distribution and structural difference of minerals are relatively large.
Oxidation of the ore has a certain, limonite ores are hematite oxide minerals and oxide ore index of 22%, is moderately oxidized magnetite ore, magnetite accounts for 89% of the metal content of the mineral Limonite and hematite account for 11% of metal minerals. Magnetite is distributed in various forms in ore. First, it is a granular aggregate, mainly composed of coarse and fine-grained magnetite. The aggregates form a dense mass structure, which is visible between magnetite particles. Hematite fine veins. Second: sparse granular aggregates, magnetite is filled with limonite between particles or cut by limonite veins. Magnetite particles are generally relatively broken, and the particle size is mostly less than 0.074 mm. The third type is coarse-grained compact massive magnetite. The magnetite has a coarser particle size. The general grain size is greater than 0.1 mm. The hematite mineralization along the edge of the magnetite is very developed, and the hematite is replaced by magnetite. Limonite and hematite mostly exist in the form of colloidal aggregates. Some limonites have an annulus structure, and the ring belt is wrapped with a large amount of dusty components, which proves that the formation of limonite is related to multi-stage oxidation. The structural characteristics of iron ore and hematite determine that magnetite cannot be separated and the recovery is more difficult.
The iron ore type is medium oxidized magnetite ore, the original ore total iron is 59.20%, the iron in the magnetic iron is 47.55%, and the magnetic iron accounts for 80.26% of the total iron. Since the main iron-bearing mineral of the iron ore is magnetite, magnetite is a strong magnetic iron ore, but the magnetite is partially oxidized and belongs to a moderately oxidized magnetite ore. Since some of the magnetite is oxidized, the magnetism of this part of the magnetite is weakened. According to the nature of the ore, the test uses two kinds of processes; 1. The weak magnetic + medium magnetic process, grinding fineness -200 70%, weak magnetic field strength 1500 Oersted, medium magnetic field strength 4000 Oersted, weak magnetic rough selection, medium magnetic sweep selection, all iron grade 64.81%, total iron recovery rate 94.92%. Second, the magnetic field magnetic separation process, grinding fineness -200 mesh 70%, field strength 4000 Oster-5000 Oersted, a rough selection, all iron grade 65.55%, total iron recovery rate 93.98%, for magnetic The recovery of iron is 100%.
Second, the conclusion
(1) Summary of Process Mineralogy Research
The mineral composition of the upper iron ore in Jiangsu XXXX is relatively simple. The ore minerals are magnetite, hematite, limonite and trace pyrite. Mainly carbonate gangue minerals, quartz, white mica, magnetite mineral content accounted for 89% of the metal, limonite, hematite accounting for 11% of the total amount of metal minerals, mainly magnetite equiaxed particulate, All of them are metamorphosed and recrystallized to form an enrichment. Most magnetites have a particle size of less than 0.1 mm, and are mostly particulate. Limonite and hematite mainly exist in the form of colloidal aggregates, and the formation of some limonite is related to multi-stage oxidation. The structural characteristics of the brown hematite determine the difficulty of recovery. The iron ore is a moderately oxidized magnetite.
(2) Test process and test indicators
The iron ore is a moderately oxidized magnetite, that is to say, some of the magnetite is oxidized, and the magnetite is weakened. Therefore, two processes are used according to the ore property test; the first process is weak magnetic + The medium magnetic field process, weak magnetic rough selection, medium magnetic sweep, the average grade of all iron is 64.81%, and the total iron recovery rate is 94.92%. The second process flow is: medium magnetic field process, the medium magnetic field strength is 4000-5000 Oersted, the test index is 65.55% of the total iron grade, and the total iron recovery rate is about 94%.
(III) Chemical analysis of iron concentrates and tailings
The iron concentrate is analyzed by chemical multi-element, all impurities are not exceeded, and the iron concentrate meets the national standard first-class requirements. The final tailings are chemically multi-element analysis, and there are no recycled minerals in the tailings.
(4) Problems in the sedimentation test of iron concentrates and tailings
Since the iron concentrate contains a small amount of erythro-iron, the particle size is fine. In the iron concentrate sedimentation velocity test, a small amount of suspended solids affects the observation. The tailings contain mud and fine-grain red brown iron. When the tailings sedimentation test, it also affects the observation. It is recommended to add a little flocculation to help the sink.
(5) Recommended process
This test uses two kinds of process flow: one, weak magnetic rough selection, medium magnetic sweeping process flow; second, medium magnetic field magnetic separation process, the two process flow test indicators are similar, the first process flexibility is large, The second process is simple, and it is recommended that the mine and the designer jointly negotiate the process.
(6) Economic benefits
Through detailed ore selectivity test research, the iron ore mine is provided with a set of economical and technically feasible process flow, and the economic benefits are initially estimated. The daily processing of 500 tons of iron ore processing plant, 300 days of annual work, annual profit and tax of 78.655 million yuan, economic and social benefits are substantial, the mine has a development value, this test can be used as beneficiation plant design basis.
(7) Raw ore grade
The total iron grade of the test sample taken this time is 59.20%, but from the geological report, the average grade of total iron in the mine is only 42.5%, which is 10% depleted at the time of sampling, and the ore-selecting grade is 38.3% of the total iron (which has reached the industrial grade requirement). The sampled product has a large deviation from the average grade of the mine. If it is to be fully in line with the actual production, it is recommended to re-take the sample that meets the average grade of the mine for process verification test.
(8) Dry selection and tailing