Production process of lean magnetite ore beneficiation

The lean magnetite ore in Anshan area is a lean magnetite ore with high silicon and low sulfur and phosphorus. The content of red and limonite is low, and the content of iron silicate and iron carbonate is relatively high. At this time, many large-grained gangues can reach the monomer to dissociate. According to the nature of the lean magnetite ore in Anshan area, it is considered to select stage grinding and single magnetic separation process to process the lean magnetite ore in Anshan area. Compared with the combined magnetic-levitation process, together with the supply of qualified iron concentrates that meet the requirements of ironmaking, a single magnetic separation process has the advantages of simple process flow, low operating cost, high iron recovery rate, and reliable process. The depleted magnetite ore from the distribution is processed by a single magnetic separation process, and now it is mostly used to combine magnetic separation equipment and screening equipment. Therefore, it is believed that “stage grinding, single magnetic separation-fine screen regrinding process” is a suitable process for processing lean magnetite ore in Anshan area. This process is used for Dagushan ore, mixed ore of Yanqianshan ore and Gongchangling lean magnetite The ore was separated for sorting, and all achieved better sorting targets.
1. The nature of the ore
(1) The chemical composition of the ore The multi-element analysis results of Dagushan ore, Yanqianshan ore and Gongchangling lean magnetite ore are shown in Table 1, and the phase analysis results are shown in Table 2.
It can be seen that the Dagushan ore, Yanqianshan ore and Gongchangling lean magnetite ore in the Anshan area are all lean magnetite ore with high silicon and low sulfur and phosphorus, and the content of iron silicate and iron carbonate is relatively high.
(2) The composition and structure of the ore deposits. The primary types of Dagushan ore, Yanqianshan ore and Gongchangling lean magnetite are: magnetite quartzite, hornblende (green mud) magnetite quartzite, and false hematite ore. Rock etc. The structure of the ore is dominated by a band-like structure, together with a crumple-like structure and a breccia-like structure. The structure of ore is dominated by granular metamorphic structure, which develops informative structure, including structure, etc. together.
(3) Granularity of ore inlaid Dagushan ore, Yanqianshan ore and Gongchangling lean magnetite ore are all fine-grained and unevenly interspersed lean magnetite ore. The uniform grain size of the Qianqianshan ore iron deposit is 44.95μm, and the uniform grain size of the gangue deposit is 71.20μm. The average grain size of the iron deposits in Dianxi District of Dagushan Iron Mine is 38.54μm, the average grain size of gangue deposits is 53.52μm; the average grain size of Diedong iron deposits is 40.06μm, and the average grain size of gangue deposits is 67.74μm. The average particle size of Gongchangling lean magnetite iron deposit is 49.74～69.65μm, and the average particle size of gangue deposit is 69.55～100.20μm.
Second, the determination of the process and the results of the selection
(1) Determination of stage grinding, single magnetic separation-fine sieve regrinding process Because Dagushan ore, Yanqianshan ore and Gongchangling lean magnetite ore are all poor magnetite ore with unevenly distributed fine grains, and their veins The grain size of the ore deposit is relatively coarse, and many large particles of gangue can reach the monomer dissociation during rough grinding. Therefore, it is considered to choose stage grinding, stage sorting process for sorting, and throw away some low-grade tailings in advance to reduce The processing capacity of subsequent grinding and sorting operations. According to the results of the magnetic separation tube sorting experiment, Dagushan ore, Yanqianshan ore and Gongchangling lean magnetite ore can be thrown away below 10% when the grinding particle size -0.074mm is 55%-65%. Tailings with a yield of more than 40%. According to the phase analysis results of Dagushan ore, Yanqianshan ore and Gongchangling lean magnetite ore, the main ore is magnetic ore, there are a few iron silicate and iron carbonate, and the content of red and limonite is very small. Because of the high content of iron silicate and iron carbonate, no matter what method is selected, the tailings grade will be higher, and the content of red and limonite is small, so a single magnetic separation process is considered. And compared with the combined magnetic-levitation process, the full magnetic separation process has the advantages of simple process flow, low operating cost, high iron recovery rate, and reliable process when supplying qualified iron concentrates that meet the requirements of ironmaking. For the lean magnetite ore with unevenly embedded fine particles, magnetic separation equipment and screening equipment are now mostly used. The sieve is used to select the products under the sieve to obtain high-grade concentrates. The products on the sieve are re-grinded and fed into the magnetic separation, and the magnetic fines are fed into the fine sieve. The disadvantage of the post-magnetic process is that it not only improves the sieving grade of the fine sieve, but also reduces the amount of ore supplied by the fine sieve, which can give full play to the effect of the fine sieve and increase the screening power. Following the emergence of high-efficiency magnetic separation equipment and high-efficiency screening equipment, this single regrinding process of magnetic separation and fine sieve has become an economical and useful process for obtaining high-grade iron ore concentrates.
(2) The results of three kinds of ore sorting. The Dagushan ore, the Yanqianshan ore and the Gongchangling lean magnetite ore were sorted by “stage grinding, single magnetic separation-fine sieve regrinding process”.
Dagushan ore and Yanqianshan ore are mixed and fed into the “stage grinding, single magnetic separation-fine screen regrinding process” for separation. The grade of the original ore is 29.73%, and the primary grinding particle size of -0.074mm accounts for 65%. Under the condition that the secondary grinding particle size -0.074mm particle size accounted for 87%, and the regrind particle size -0.074mm particle size accounted for 91%, the classification goals achieved were: 67.44% concentrate grade, 34.06% concentrate yield, and metal recovery rate 77.26%, tailings grade 10.25%. Now, the process has been successfully used in the Dagushan Concentrator. After the process is selected, the grade of the leather concentrate in the Dagushan Concentrator has reached 67.5%, which is 1% higher than the concentrate grade before the transformation. Production capacity. This provides rich practical experience for the selection of “stage grinding, single magnetic separation-fine screen regrinding process” to process lean magnetite ore. Gongchangling lean magnetite ore is sorted by “stage grinding, single magnetic separation-fine sieve regrinding process”. The grade of the original ore is 31.23%, and the primary grinding particle size -0.074mm accounts for more than 60%, and the secondary grinding Under the condition that the particle size -0.074mm grain size accounts for more than 85%, and the regrind particle size -0.074mm grain size accounts for more than 85%, the sorting targets obtained are: 67.80% concentrate grade, 37.04% concentrate yield, and 80.41 metal recovery rate. %, tailings grade is 9.27%. Now, the Gongchangling No. 1 Selection Workshop has adopted this process for production technology transformation. The modified tailings grade can be reduced by 1% compared with the original maglev combined process. The metal recovery rate is improved, and the process is short and the process is short. In short, it saves the cost of flotation reagents and reduces production costs. The use of “stage grinding, single magnetic separation-fine screen regrinding process” in Gongchangling further clarifies that this process is a reasonable and advanced process for processing poor magnetite ore in Anshan area.
Three, process characteristics analysis
(1) Stage grinding, rough grinding and polishing. Selecting stage grinding and accustomed to the uneven particle size of the original ore, Dagushan ore, Yanqianshan ore and Gongchangling lean magnetite ore are selected for “stage grinding, single magnetic separation-fine sieve regrinding process” for separation. Under the condition that the primary grinding particle size is -0.074mm, 60%~65%, the use of a magnetic separator for separation can throw away low-grade tailings with a yield of about 40%, reducing subsequent grinding and The processing volume of the sorting job. Throw away the gangue and lean conjoined organisms that have reached the monomer dissociation as soon as possible to prevent circulation in the process. This is the preferred plan in the beneficiation process.
(2) Single magnetic separation, simple process. A single magnetic separation process is used to process the lean magnetite ore in the Anshan area. It is used to the ore properties of the original ore. Compared with the process of using the magnetic-float combined process to process the lean magnetite ore, the process is short and the process is simple. There is little industrial useable iron loss in the tailings. , The metal recovery rate is high, and the cost of flotation reagents is saved, and the production cost is reduced. (3) Magnetic screen first, fine screen and then grinding. The raw ore throws out qualified tailings under the condition of coarse grinding. After the coarse concentrate is separated by weak magnetic and fine grinding, the products on the screen are mostly rich contiguous and non-dissociable inclusions, which must be reground to make the fine particles embedded. The iron ore deposits that exist in the form of inclusions are abundantly dissociated, and they can then select and obtain qualified concentrates. Re-grinding products use the sorting process of magnetic first and then sieving, which overcomes the disadvantages of large amount of ore and large regrinding circulation caused by the fine sieve of magnetic sieve after sieve. The amount of ore feed and regrind can give full play to the effect of the fine sieve and improve the sieving power.
Four, conclusion
(1) “Stage grinding, single magnetic separation-fine sieve regrinding process” is used to the uneven distribution of poor magnetite in Anshan area. The content of harmful impurities such as sulfur and phosphorus in the original ore is low. The useful minerals are mainly magnetic minerals. The nature of the ore with little red and limonite content.
(2) The “stage grinding, single magnetic separation-fine screen regrinding process” is technologically advanced and economically reasonable. The raw ore throws qualified tailings under the condition of coarse grinding, which reduces the processing volume of subsequent grinding and separation operations; the use of a single magnetic separation process has the advantages of high metal recovery rate, simple process, and low production cost; fine sieve Grinding, so that the fine-grained interspersed and the iron ore deposits existing in the form of inclusions are fully dissociated. The magnetic field is first sieved, which not only improves the sieve level of the fine sieve, but also reduces the amount of ore feed and regrind of the fine sieve. It can give full play to the effect of the fine sieve and improve the sieving power. (3) The use of “stage grinding, single magnetic separation-fine screen regrinding process” to process Dagushan ore, Yanqianshan mixed ore and Gongchangling poor magnetite ore have achieved satisfactory results, which fully proves that the process is an Anshan Reasonable and advanced technological process of regional lean magnetite ore.