The beneficiation method and technological process used in the beneficiation ofdepend on factors such as the type of ore deposit, the nature of the ore and the mineral composition. In view of the similar nature of titanium primary ore (vein ore), the type of target mineral is relatively simple, and the beneficiation method and process used have strong commonality; while the titanium and zirconium minerals in the titanium placer and zirconium placer deposits are mostly similar to monazite The symbiosis of yttrium, xenotime, cassiterite and precious metals is a comprehensive placer deposit. Therefore, the beneficiation of titanium and zirconium placer deposits is mostly integrated into the common beneficiation process from roughing to beneficiation. Based on this, in this section, the beneficiation of titanium and zirconium ore is divided into two parts: primary titanium ore (vein ore) beneficiation and titanium and zirconium placer beneficiation.
1. The beneficiation of primary titanium ore (vein ore) The titanium primary ore (vein ore)
currently used in industry is all titanium-containing composite iron ore. In order to utilize the titanium resources in it, depending on the nature of the ore, the entire beneficiation process can be divided into three stages: pre-selection, iron beneficiation and titanium beneficiation.
The selection of titanium can be divided into two stages: rough selection and selection.
(1) In the pre-selected titanium vein ore, when it is crushed to a certain degree of coarse-grained state, a considerable amount of gangue reaches the basic monomer dissociation. These coarse-grained monomer gangue can be discarded by pre-selection operation. To achieve the purpose of increasing the processing capacity of the processing plant and improving the selected grade. The pre-selection operation can be carried out at the appropriate stage of the coarse, medium and fine crushing operation before the grinding operation according to the nature of the ore. Commonly used methods of preselection are magnetic separation and reselection.
(2) Iron-processing titanium-containing composite iron ore. At present, the main purpose of industrial use is to obtain iron concentrate for iron smelting; for ore with high vanadium content, it is to obtain vanadium iron ore for iron smelting and vanadium extraction. The iron selection is carried out by a simple and effective magnetic separation method. After the selected ore is crushed (or pre-selected) and ground to make it reach the optional monomer dissociation degree, iron concentrate or vanadium iron concentrate is selected by drum or belt weak magnetic field wet magnetic separator. Magnetic separation tailings are the raw materials for comprehensive recovery of titanium. Some ore iron and titanium minerals are densely embedded, and it is difficult to obtain a separate concentrate by a single beneficiation method. Only the tailings are discarded by gravity separation, and the obtained iron and titanium mixed concentrate is directly roasted and smelted to produce High-purity pig iron and titanium slag products.
(3) The recovery of titanium in the titanium vein ore is carried out in the magnetic separation tailings after the iron concentrate is selected. The methods used to select titanium include gravity separation, magnetic separation, electric separation and flotation, which vary according to the nature of the ore, and suitable beneficiation methods are used to form different technological processes for separation. At present, the beneficiation process used in industry has the following types:
gravity separation-electrical separation process gravity separation-electrical separation process is characterized by the use of gravity separation for rough separation and electrical separation for selection. The equipment used in heavy separation is mainly spiral concentrator (including spiral slide), followed by shaker. The use of cone concentrators for heavy separation has now reached the stage of industrial testing, but has not yet been formally used in production. In the roughing stage of re-election, the purpose is to discard low-density gangue and obtain coarse concentrate for power supply. The equipment used in the electric separation is a roller electric separator, whose purpose is to further enrich the heavy separation coarse concentrate, so that the product reaches the final concentrate standard.
For sulphur-containing ore, flotation is usually used as an auxiliary process to remove sulfide ore between the roughing and beneficiation processes. Gravity separation-magnetic separation-flotation process flow Gravity separation-magnetic separation-flotation process is characterized by the first classification of the raw ore that enters the titanium separation. The coarse particle level adopts gravity separation rough separation, magnetic separation selection, and fine particle level. Use flotation. The reselection adopts a shaker, and the magnetic separation adopts a dry magnetic separator. The particle size of the flotation feed is generally -0.074 mm, and the flotation agents used are sulfuric acid, sodium fluoride, oleic acid, diesel oil and pine oil.
Single-flotation process The single-flotation method is a more effective method for separation of fine-grained embedded titanium veins. The single flotation process is simple, and the operation and management is convenient. However, because the consumption of chemicals will increase the cost, and there are environmental protection problems caused by tailings discharge, the current industrial application is not extensive. The flotation agents used in titanium flotation include sulfuric acid, tall oil, diesel oil and emulsifier Etoxolp-19. In order to improve the flotation effect, it has a certain effect on the high concentration and long time stirring of the selected ore and the flotation agent before flotation.
2. Beneficiation of titanium-zirconium placer
The main deposit type of titanium-zirconium placer is coastal placer, followed by inland placer. Titanium-zirconium placer is produced by weathering, crushing and enrichment of primary ore under natural conditions. It has the advantages of easy mining, easy selection, low production cost, good product quality, many types of associated minerals, and high comprehensive recovery value. It is one of the more ideal mineral resources.
Titanium-lead placer is currently the world’s main source of mineral products such as ilmenite, rutile, zircon and monazite. For titanium and zirconium placers, except for a small number of ore bodies that have overlying layers that need to be stripped, they can generally be mined by thousand mining or ship mining machinery without stripping. Dry mining machinery includes: bulldozers, scrapers, loaders and bucket wheel excavators, etc.; mining ships used for ship mining include chain bucket, suction and bucket wheel types. The mined ore is transported to the roughing plant by belt conveyor or sand pump pipeline. The titanium and zirconium placer ore dressing plant is divided into two stages: roughing and beneficiation.
(1) The ore that is sent to the roughing plant for roughing is firstly subjected to necessary preparation operations such as deslagging, screening, grading, desliming and concentration, and then sent to the roughing process for sorting. The purpose of roughing is to separate the selected ores according to the different mineral densities, discard low-density gangue mineral tailings, and obtain a heavy mineral mixed concentrate with a heavy mineral content of about 90%, which is used as feed for the beneficiation plant. The roughing plant is generally integrated with mining operations to form a mining plant. In order to adapt to the characteristics of placer deposits, general roughing plants are built as mobile, with floating boats and land tracks, crawlers, pallets, and regular demolition.
For rough separation of titanium and zirconium placers, equipment that has large processing capacity, high recovery rate and is easy to use in mobile concentrators is generally selected. The more common ones are cone concentrators and spiral concentrators, and a small amount of shakers are used. The above-mentioned equipment is used for single use and also used in conjunction: single cone concentrator is mainly used for roughing plants with large scale or high content of heavy minerals in the original ore; most plants use cone concentrators for roughing and spiral concentrators for refining; Some small-scale concentrators often use a single spiral concentrator for roughing.
(2) The selected titanium and zirconium placers are mostly comprehensive deposits containing several valuable minerals. The purpose of the selection is to effectively separate and purify the valuable minerals in the coarse concentrate to achieve their respective concentrates. Quality requirements make it a commercial concentrate. The selection plant is generally built as a fixed type. The coarse concentrate is transported to the beneficiation plant for processing by means of automobile, train or pipeline transportation.
The selection operation is divided into two stages, wet and dry, and dry operation is the main one. According to the nature of the coarse concentrate, partial wet operation is usually used in the first stage of the beneficiation process. Sometimes there is a process of alternating dry and wet methods in the selection process, but from the perspective of energy consumption and simplification of the process flow, we strive to reduce this process when possible.
The types of wet processing operations in the beneficiation plant include: re-election using a shaker or spiral concentrator to further discard the low-density gangue minerals remaining in the coarse concentrate. For the coarse concentrate with salt content, it also has cleaning salt content. Use wet magnetic separation to pre-select part of the easy-to-select titanium concentrate, reduce the amount of dry separation into the beneficiation; add sodium hydroxide, hydrochloric acid, dilute hydrofluoric acid, sodium metabisulfite, etc. to the coarse concentrate The agent is stirred at a high concentration to achieve the purpose of removing the pollution on the mineral surface and improving the selection effect; the flotation method is used for the selection of zircon and monazite products.
Dry selection is sorting according to the differences in magnetism, conductivity, density, etc. among the minerals in the product. Depending on the composition and properties of the coarse concentrate, the structure of the dry separation process will vary greatly. For the dry separation of coarse concentrates with more complex mineral composition and more comprehensive recovery minerals, the process is more complicated, there are more operations, and the process structure changes greatly; for coarse concentrates with simple mineral composition, the dry separation process is very simple . Magnetic separation is the use of magnetic separators of different types and field strengths. Theof minerals with different magnetic susceptibility coefficients
commonly used magnetic separation equipment for the separationare: disc type (single disc, double disc, three disc), cross belt type, roller type Magnetic separators such as, counter-pole type, etc., in the dry separation process usually first use weak magnetic separation to separate strong magnetic minerals-magnetite, and then use a medium magnetic field to select most of the strong and easy-to-select titanium Iron ore products. Strong magnetic separation is used to separate some of the weaker magnetic ilmenite and monazite from the non-magnetic minerals such as zircon, rutile, and white titanium. Electric separation is the use of the difference in conductivity between the minerals in the coarse concentrate for separation.
There are three types of electric separators: roller type, plate type and sieve plate type. Electric separation is often used in the dry separation process of coarse concentrates for the grouping of conductors and non-conducting minerals; the separation of rutile and zircon; the selection of refractory ilmenite, zircon, monazite and other minerals. In production practice, sometimes operating conditions such as changing the magnetic field and electric field strength are used to alternate electric and magnetic separation operations to enhance the separation effect.