Tantalite-Nipponite coarse concentrate selection

Tantalite ore - columbite crude concentrate composition generally complex, difficult separation, magnetic separation is often necessary, re-election, floating reselection, flotation, electrostatic separation, chemical treatment or the like in one to two kinds or more of combinations of . In particular tantalite, columbite and difficult to separate certain mineral material, more in combination selected from the group do not need to use a variety of methods. For example, coltan-niobite is separated from garnet and tourmaline , and magnetic separation, electric selection or flotation is usually used.

Magnetic separation

Their specific susceptibility: tantalite is 2.4 × 10 ^-5 cm ³ / g, columbite of 2.5 × 10 ^-5 cm ³ / g, columbite of 2.5 × 10 ^-5 cm ³ / g, yttrium brown The antimony ore is 5.8××10 ^-5 cm ³ /g, and the garnet and tourmaline are changed with the iron content. When the content of Fe ₂ O ₃ is increased from 7% to 25%, the specific magnetic susceptibility is determined by 11×10 ^-6 cm/g increased to 124×10 ^-6 cm/g (11 times increase), when the content of Fe ₂ O ₃ increased from 0.3% to 13.8%, the specific magnetic susceptibility of the tourmaline was 11× 10 ^-6 cm ³ /g increased to 124 × 10 ^-6 cm ³ / gram (11 times increase). In order to improve the selectivity of mineral separation in a magnetic field, it is generally treated with acid (solid: liquid = 1:5) for a short time (5 to 15 minutes) to remove iron from the mineral surface and then separated in a magnetic field of different strength. From garnet and tourmaline, bismuth concentrate can be obtained.

Electrical separation

The material is first subjected to narrow-level screening and classification, and then separately heated to perform electric selection in the composite electric field: greater than 0.2 mm, the granularity is generally low voltage (20 to 35 kV), large pole pitch (80 to 100 mm), Slow speed (low centrifugal force) (roller or drum rotation is 33 to 38 rpm). -0.2～+0.08mm grain size generally uses high voltage (35～45 kV), small pole pitch (50～80mm), fast rotation speed (high centrifugal force) (roller rotation number is 70～118 rpm) . The coltan-niobite can be separated from the garnet.

Flotation separation

Sodium hexadecyl sulfonate is used as a collector, and a fluorine compound is used as a regulator to separate the coltan from the garnet.

Separation of coltan from monazite

The coarse fraction is usually selected by electro-election: fine-grain grade (-0.075 mm) using oleic acid or rice sugar oil as a collector, sodium carbonate (Na ₂ CO ₃ ) as a regulator, sodium silicate (Na ₂ SiO ₃ ), sodium sulfide (Na ₂ S) as inhibitors of _{(Na 2 SiO 3 :Na 2 S} = 3:1), monazite floating at pH9, and make the iron tantalum (niobium iron ore) is separated from the monazite.

Separation of fine spar and cassiterite

The coarse fraction is usually electrostatically selected (voltage 16 kV); the fine fraction is first treated with 2% hydrochloric acid for 15 minutes, then sodium alkyl sulfate (600 g/ton) is used as a collector, and sodium fluorosilicate (with sodium fluorosilicate) Na ₂ SiF ₆ ) acts as an inhibitor, and the cassiterite floats under the condition of pH 2 to 2.3, and the fine spar can be separated from the cassiterite.

Separation of coltan and magnetic cassiterite

Coarse fraction separation generally use a wind shaker; fine grade, Guangzhou, China Research Institute developed ferrous metal roasting (800 ~ 900 ℃) new magnetic separation process can be well separated from the tantalum and niobium ore, gold tantalum Red stone and cassiterite.

Separation of coltan and black tungsten ore

Water smelting is usually used. First, the material is ground to -0.04 mm, calcined with sodium carbonate (Na ₂ CO ₃ ) (800 ° C), or boiled with concentrated alkali at normal pressure. After filtration, the residue is decomposed with HCl (5%) to obtain artificial mash. Concentrate. The filtrate is a sodium tungstate solution, and after oxidation (pH 2 to 2.5), extraction, neutralization, crystallization, and the like, a tungsten oxide (WO ₃ ) product can be obtained.

Separation of coltan and zircon

Magnetic separation or flotation can be used. Flotation can use sodium oleate as a collector, lead chloride, water glass and lead chloride, and oxalic acid as a regulator to separate the coltan from zircon.