Method for increasing yield of reverse flotation iron concentrate and reducing consumption of caustic soda

Abstract

The invention relates to a method for increasing the yield of reverse flotation iron concentrate and reducing the consumption of caustic soda. The method comprises the steps of (1) adding a mineral grain monomer dissociator in the ore crushing and grinding process during reverse flotation of iron concentrate; (2) adding calcium oxide to runners or pipelines upstream strong magnetic tailing big wells, flotation tailing big wells and water treatment units; and (3) adding medicament for removing silicate to a concentrate filter unit and / or any position between a reverse flotation unit and the concentrate filter unit. According to the method, the mineral grain monomer dissociator is added in the ore grinding process, so that the mineral grain monomer dissociation yield can be increased in thecondition that the grinding degree is not increased, thereby increasing the yield of the iron concentrate; the calcium oxide is added at fixed points, so that the carbonation is eliminated, and the pHvalue of circulating water is increased, thereby reducing the consumption of caustic soda; and the medicament for removing silicate is added at fixed points, so that water soluble sodium silicate which has effect on the concentrate filter effect is removed, and the concentrate filter efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of iron ore reverse flotation, in particular to a method capable of reducing the consumption of caustic soda while increasing the yield of reverse flotation iron ore concentrate. Background technique [0002] Such as figure 1 As shown, the existing iron ore reverse flotation process is: iron ore→coarse crushing (generally using crushing equipment such as jaw breaking or semi-autogenous grinding)→sieving (fine particles under the sieve enter the grinding unit 1, and the screened residue Coarse grains return to coarse crushing) → Grinding unit 1 (with ball mill and cyclone, fine-grained ore enters the big well 2 before magnetic separation as overflow, and coarse-grained ore flows back to the ball mill as underflow) → Big well 2 before magnetic separation (The overflow enters the water treatment unit 11, and the underflow enters the strong magnetic machine 3)→The strong magnetic machine 3 (the strong magnetic ...

AI Technical Summary

Problems solved by technology

[0006] 1) At present, most of the domestic lean iron ore ores have fine crystal grains, and the mineral grains and gangue grains are not easy to separate. To increase the dissociation degree of the minerals, the ore must be ground finely. If the monomers are not dissociated, the mineral processing cannot be carried out. However, if the ore is too finely ground, it is also very unfavorable to the beneficiation operation. First, the useful mineral particles after grinding are too small, the sedimentation speed is slow, and it is easy to flow away with the overflow of the big well, resulting in metal loss and a decrease in yield

Second, if the grinding is too fine, the specific surface of the ore will be too large, and the reverse flotation agent will be consumed too much, which will increase the cost of the reverse flotation agent

[0007] 2) In the process of water treatment, simply add water purifying agents, the inorganic agents are acidic agents, which neutralize the alkali in the water body, reduce the pH value of the water body, increase the caustic soda consumed by reverse flotation, and cause the unit consumption of alkali rising costs;

[0008] 3) The concentrate filter unit 10 simply adds sulfuric acid or filter aid, and its filter effect is not ideal enough and cannot reach the best state; at the same time, it neutralizes the alkali in the ore pulp, so that the pH value of the filtrate is reduced, thereby reducing the pH value of the filtrate during reverse flotation. Increase in alkali consumption

In addition, in the existing reverse flotation process, the process for the concentrate pulp to leave the reverse flotation unit 6 and reach the concentrate filter unit 10 is very long, causing the concentrate pulp to exist for too long under dynamic conditions. And it contains residual silicon dioxide, silicon dioxide and sodium hydroxide react to form sodium silicate, sodium silicate will seriously affect the filtration effect of the concentrate filtration system, the reaction formula is: 2NaOH+SiO 2 →Na 2 SiO 2 +H 2 o

[0009] 4) In most of the existing reverse flotation processes, the water entering the ring water system includes 1) replenishing new water; 2) rainwater and snow water; the water discharged from the ring water system includes 1) evaporated water; 2) seeping into the ground Water; 3) Moisture contained in the concentrate powder; sodium ions, sulfate ions, and chloride ions entering the ring water system cannot be discharged from the system through evaporating water, but only through underground water seepage and the concentrate powder. The water leaves the system; and the discharge of these two parts is very small, so it is easy to cause the enrichment of various ions in the ring water system. When the enrichment reaches a certain level, it will affect the beneficiation, and once this happens very difficult to solve

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