I. Research on various ore dressing processes in foreign countries
At present has found TiO2 content greater than 1% of titanium minerals are more than 140 kinds of, but with industrial significance only ilmenite, rutile, chalcocite, titanite, titanium mud calcium cerussite, titanium magnetite and anatase and so on a few kinds of, the most important of which is ilmenite and rutile.
Primary titanium deposits is the most important titanium resources, primary ores of titanium reserves in the world a one accounted for 70% ~ 80% of the titanium reserves in alluvial ores accounted for only 20% ~ 30% of foreign beneficiation of primary ores are often used in re-election, magnetic separation, flotation, electrowinning and other methods, the following is an introduction to several of the most effective foreign metallurgical process joint flow.
(1) ilmenite - magnetite type of beneficiation
This type of ore ilmenite is often an independent package dipped in magnetite and non-metallic minerals, the principle of dealing with this type of ore is as coarse as possible to throw the tail, and then grinding and magnetic separation, selected ilmenite concentrates, sulphide should be floated out of sulphide concentrates, and then flotation of fine-grained ilmenite.
The common characteristics of selecting this type of ore are:
(1) the treatment of fine-grained embedded ores generally do not use re-election, but the use of magnetic - flotation joint process, for coarse-grained embedded uneven ores, the use of magnetic - heavy - flotation joint process. (2) If the ore contains sulfide to be in the flotation of titanium before floating sulfur; the presence of apatite, the process should also be selected phosphorus operations.
(3) ilmenite flotation generally use the capture agent is a mixture of fatty acids and neutral hydrocarbons.
(2) Hematite - ilmenite type of ore dressing
Usually the hematite and ilmenite in this type of ore are in fine-grained close coexistence, and beneficiation can only select the titanium-iron mixed concentrate from it, and then smelt it by pyrometallurgical method in order to obtain pig iron and high titanium slag. Canada and Egypt have deposits of industrial significance. For example, the typical process of Canada's Lakkio beneficiation plant, with heavy media cyclone treatment, the latter with a spiral concentrator, the resulting concentrates are combined, dewatered and dried and then sent to roasting, in order to remove sulphur from the concentrate.
3) Beneficiation of Calcite-Titanium Magnetite Types
Beneficiation of titanomagnetite is selected by wet magnetic separation, followed by flotation of calcite with fatty acid-based traps, and ilmenite flotation after washing and de-drugging of the products in the tanks.
(4) titanium niobium calcium cerium ore beneficiation
This type of ore is often accompanied by nepheline, feldspar, nepheline, apatite and a small amount of titanium brown silicate, cottonite, and hornblende. Coarse TiNbCaCe can be recovered by re-election, while fine TiNbCaCe in the tailings can be recovered by flotation. The process includes roughing apatite with Tar oil, soda ash and water glass in alkaline medium, separating nepheline, and finally obtaining titanium niobium calcium cerium ore concentrate.
(5) Titanite beneficiation
There are titanite resources in the United States, Canada, Madagascar. Titanite as titanium raw material has attracted attention in the last 40 years. After apatite is selected, titanite is enriched in the froth of the reverse flotation, the froth product of the reverse flotation is deslimed, and the titanite concentrate can be selected by concentrating without trapping agent. Magnetic separation can select the residual nepheline, non-magnetic part is titanite concentrate.
(6) White titanite beneficiation
White titanium stone is ilmenite alteration products, both in the alluvial and primary ores are endowed with white titanium stone. Primary white ilmenite deposits are endowed with quartz, white ilmenite and rhodochrosite. The metallic minerals are closely co-occurring with the quartz. The ore type can be subdivided into albite-type, albite-rutile-type and oil-bearing rutile-type. In order to remove the quartz in the white ilmenite concentrate, various methods have been studied, such as high-pressure leaching, fluidised chlorine roasting, blast furnace smelting and sintering with soda, etc. However, no matter which method is used, the oil in the titanium concentrate must be removed before desiliconisation.
(7) Rutile beneficiation
Rutile primary deposits and alluvial ores compared to the secondary significance. The beneficiation of primary rutile-garnet ores associated with ancient basal metamorphic rocks - amphibolites and garnets has been studied. The beneficiation process is based on flotation and magnetic separation. At the same time, garnet, lanzanite and other associated minerals are recovered.
8) Beneficiation of anatase
Reiterite is a new type of titanium raw material, and there are large Reiterite resources in Araxa, Sali Holding and Tapira in Brazil. These deposits are formed under specific weathering conditions, and are composite deposits consisting of iron, phosphate, niobium and rare earth. The raw ore is first deslimed, crushed, magnetised and classified to obtain a titanium crude concentrate product, then ground, magnetised, classified and filtered to obtain a high grade anatase concentrate product. Then after magnetisation roasting and magnetic separation, the grade of concentrate TiO2 can reach 80%.
Second, the domestic beneficiation process research
Beneficiation process of ilmenite depends on the nature of the material. Due to the density of titanium ore relative to the vein minerals, can be used for pretreatment or roughing re-election tailing; magnetic separation is widely used in the selection of titanium-containing minerals; electrowinning is used in titanium minerals selection, when the crude concentrate contains ilmenite, rutile, but also contains zircon and other non-conducting minerals, can be used to separate the electrowinning. Flotation method is used for primary titanium ore separation, especially for separation of fine-grained titanium ore, sometimes also used in the selection of crude concentrate.
1) Re-election
Re-election method is highly valued because of its low production cost and less pollution to the environment. The earliest, from the 50's research from the magnetic separation tailings recovery of ilmenite is from the re-election method began. When carrying out the recovery of ilmenite by re-election, the difficulty of separation between minerals can generally be evaluated in advance and approximated based on the formula of the separation coefficient.
At present, new progress has been made in improving the efficiency of re-election, developing and using new equipment. Panzhihua re-election process after many years of scientific and technological research, with the re-election and the level of strong magnetic equipment with the improvement of the level of strong magnetic equipment, the establishment of the current GL full flow or GL2 strong magnetic process, so that the recovery of rough titanium significantly improved. Shaking table has been widely used in ilmenite ore dressing, especially some small mines use shaking table to get qualified concentrate. Kunming area ore samples using shaking table a shaking table process, after removing iron ilmenite TiO2 grade reached 48.82%, recovery rate of 76.00% or more.
2) Electrowinning
Electrowinning as the final gatekeeper for the production of titanium concentrate, has been widely used. Pangang titanium plant using Changsha Institute developed and produced YD -3-type high-voltage electric separator re-election of rough concentrate, the results are very good: raw TiO2 grade 28.86%, concentrate TiO2 grade 47.74%, tailings grade TiO210.63%, the recovery rate of 84.18%. 1994, the plant from the U.S. introduction of two HTP (25) 231 ~ 200 CarPco-type electric separator, the plant has been widely used as the final gateway to the production of titanium concentrate. In 1994, the plant imported two HTP (25)231~200CarPco type electric separators from the U.S.A. From the point of view of production application, this model is not suitable for separating primary ilmenite. Compared with YD-3 type electric separator, the grade of concentrate is 0.84% lower, the grade of tailings is 3.98% higher, and the recovery rate is 8.32% lower. The main reason is that Carpco-type electrowinning machine is designed for separating seashore sand ore, and it is not suitable for primary ore with high mud content.
3) Magnetic separation
Magnetic separation includes weak magnetic separation and strong magnetic separation. The function of weak magnetic separation is to separate out the titanomagnetite remaining in the tailings of magnetic separation, so as to facilitate the smooth progress of strong magnetic separation. The purpose of strong magnetic separation is to discharge qualified tailings, improve the grade of titanium flotation and reduce the amount of titanium flotation ore.
SLon Vertical Ring Pulsating High Gradient Magnetic Separator is a new type of high-efficiency magnetic separation equipment invented in the late 1980's. After more than ten years of continuous research, it has been unanimously recognised by domestic and foreign users and has been highly valued and paid close attention to with its unique structure, performance and effect. In just more than ten years, SLon magnetic separator has achieved large-scale and serialisation at a fast speed, not only with SLon -750, SLon -1000SLon -1250, SLon -1500, SLon -1750, SLon -2000 transmission mode, cooling system, magnetic system protection, magnetic medium and automatic control, etc., and made a lot of improvements, so as to make the reliability and beneficiation performance have been significantly improved. Reliability and beneficiation performance have been significantly improved and enhanced.1241 At present, this equipment has been industrially applied in large-scale enterprises such as Anshan Iron & Steel, Maanshan Iron & Steel, Baosteel, Kunshan Iron & Steel and Pangangang Iron & Steel. SLon magnetic separator for selecting ilmenite with fine grain size in titanium processing plant of Pangang Iron & Steel has been successfully applied in industrial production, and has promoted the progress of titanium processing technology.
4) Flotation
(5) Combined process
As titanium minerals are often associated with many minerals, is a kind of complex composed of a variety of minerals. So whether it is ilmenite or rutile, from the structural properties and composition of the different mines that make it up the characteristics of a means of beneficiation is difficult to select high grade titanium minerals with few impurities. For this reason, before determining the beneficiation process, it is usually necessary to understand the composition and nature of titanium minerals, to find out the characteristics of each beneficiation method, on the basis of experiments to determine the process. In the selection of ilmenite, almost all kinds of beneficiation methods are used, repeatedly alternating combinations in order to achieve more satisfactory results.
For the separation of ilmenite in Panzhihua, there have been experiments on methods such as re-election and flotation, and more often than not, the combined sorting process is used, mainly: heavy-float, heavy-electric, magnetic-float and magnetic-heavy-float, and so on. Dai Huixin and others used to add dispersant, medium magnetic field to remove strong magnetic minerals, strong magnetic roughing, electrowinning and selection process, the resulting titanium concentrate grade and recovery are significantly improved. Panzhihua titanium plant was initially designed and constructed in accordance with the process of "strong magnetic - re-election - flotation - electrowinning", which only recovers coarse ilmenite. Now there are two production lines for fine grained ilmenite, one in the main process (Group I, Group II) 20,000 tonnes production scale, the recovery operation consists of cyclone concentration, desliming - pulsating strong magnetic separator magnetic separation - desulphurisation flotation - titanium flotation. The other 40,000 tonnes production line consists of cylindrical screen slag separation - pulsating strong magnetic separator magnetic separation - inclined plate classification - medium magnetic machine iron removal - desulphurisation flotation - flotation titanium flotation.
Panzhihua titanium plant micro-fine grained ilmenite recovery has been a difficult problem, titanium plant designed its own overflow through the diameter of 125 cyclone concentration, desliming - SLon - 1500 pulsating high-gradient magnetic separator - MOS for the flotation of the flotation of the flotation of the collector of the industrial test process. The results of the process examination show that: re-election - electrowinning process for -0.074mm particle size ilmenite separation effect is poor, low recovery, and strong magnetic a flotation process for the recovery of the particle size of the effect is good. Tests and production show that the production process can stably produce qualified titanium concentrate containing TiO2 ≥ 47%. The Comprehensive Research Institute of the Ministry of Geology and Mining used strong magnetism - strong magnetism in the roughing section, one coarse, two sweeps and six fines in the selecting section, and oxidized paraffin soap as the trapping agent, and obtained the TiO2 grade of 47.06% and the recovery rate of 37.58%; Changsha Mining and Metallurgy Research Institute used centrifugation - centrifugation in the magnetic section, and one coarse, one sweep, and two fines in the selecting section, and styrophosphate as the trapping agent, and obtained the TiO2 grade of ≥47%. In Changsha Institute of Mining and Metallurgy, centrifugal-centrifugal is used in the magnetic separation section, one coarse, one sweep and two finishes are used in the selection section, and styrene phosphoric acid is used as the trapping agent, and the grade of TiO2 is 46.04%, and the recovery is 56.94%. At present, the experimental research and production practice shows that strong magnetic - flotation is still a better way to deal with fine-grained ilmenite in Panzhihua.
