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Florrea depressants can offer a significant economic advanta

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Florrea-Flotation reagents|Mining chemicals|Mineral Processing_ Shenyang Florrea CO., LTD 

For more information, please contact Florrea customer service.

 Florrea depressants can offer a significant economic advantage in flotation of minerals by increasing grade and recovery of metallic concentrates.


  Florrea is world leading supplier on Selective depressants for mineral flotation processes.

Florea's flotation depressants are versatile additives that increase returns for our customers.

Application results in important savings with minimal Health, Safety or Environmental issues.

Depressants and dispersants

In mineral flotation the challenge is to maximize the recovery of desired minerals while rejecting unwanted gangue components.

Depressants are required to give a low affinity to active sites on valuable mineral surfaces and a high affinity for gangue minerals and some sulfides. Typically, depressants prevent collector adsorption or bubble attachment to unwanted mineral surfaces. This increases the selectivity of flotation, rendering certain minerals hydrophilic and preventing them floating to the surface.

Depressants for sulfide minerals

  Depressants for Pyrite

Depressants for Iron sulfide (pyrite, pyrrhotite, marcasite) depressant used in the flotation separation of base metal sulphides. Also used as an alternative partial cyanide replacement to depress iron and zinc sulfides in Pb / Zn flotation

  Depressants for Clay

  Depressants for Pyrrhotite

  Depressants for Bismuth

  depressants for copper minerals

 depressants for zinc minerals

depressants for arsenic minerals


A specialty depressant for pyrite gangue, sphalerite and pyrrhotite in lead and copper flotation systems.

Depressants for  Carbonaceous gangue.

Florrea depressants is a preg-robbing / carbon depressant designed for use in gold beneficiation processes (CIP leaching). Blanks graphitic or carbonaceous gangues, preventing them from binding to gold in solution.

Florrea provide benefits compared with many other process chemicals concerning Health, Safety and Environment:

-       Minimum regulations for storage and handling

-       Minimum harm to environment

-       Minimum toxicity level

-       Exempted from REACH registration


The mining industry faces many challenges, most notably lower quality reserves. With the decreasing quality of mined feed, more sophisticated techniques are needed to achieve industry required specifications. In many cases, the typical means of altering pH or applying different chemistries is not enough to offer the mineral selectivity needed to achieve required recovery and grade goals in flotation. Depressants are often used to increase the efficiency of the flotation process by selectively inhibiting the interaction of one mineral with the collector, for example, the depression of quartzite to allow for more optimal apatite/collector interaction, thus improving final recovery and grade.

Florrea’s flotation depressants have been custom developed for a variety of applications. They help depress gangue minerals while increasing recovery and selectivity without sacrificing grade. Our depressants have been especially effective in phosphate, silica / glass sand and iron beneficiation.

Florrea's technical team is continually developing new reagents for use in other depressant applications

Depressing Reagents

The commonest depressing reagents are lime, sodium cyanide, and zinc sulphate. Lime is extensively used to prevent pyrite from entering the concentrate of other minerals particularly copper and zinc sulphides. Its action is positive and progressive ; it is only necessary to add it to the pulp in sufficient quantity to make the pyrite unfloatable. The other minerals, are depressed at the same time, but can be floated again by the addition of sufficient xanthate, which will have no effect on the pyrite provided that enough lime has been added. If the quantity of reagents needed be prohibitive as regards cost a compromise is necessary ; the lime addition is balanced against that of the xanthate in order to give a profitable recovery of the valuable minerals in a concentrate of the required grade without too much pyrite.

The same method holds good for making a clean concentrate of sphalerite in the second stage of the separation of lead from zinc minerals in a pyritic ore. Here lime is not usually employed in the first stage, where the sphalerite is depressed by sodium cyanide and the galena brought up by carefully controlled additions of ethyl xanthate or thio-carbanilide, because the cyanide generally keeps down the pyrite as effectively as it does the sphalerite. Should lime be required, however, to depress pyrite in the first stage, one of the more powerful higher xanthates will be necessary to give a good recovery of the galena.

Sodium cyanide

Sodium cyanide is mainly used to depress sphalerite in the first or lead-flotation stage in separating lead from zinc minerals. Its action on pyrite is nearly as strong as on sphalerite, but it does not affect galena unless a large excess is added or the contact time is too long.

The effect of sodium cyanide is often intensified by the addition of zinc sulphate. The crystalline salt ZnSO4.7H2O is usually employed, although to save freight charges the lower hydrate ZnSO4.2H2O may be substituted. While no fixed rule can be laid down regulating the proportion of sodium cyanide to zinc sulphate for most efficient work, it is generally found that, for a given ore, the ratio of reagents can be kept constant, although the total quantity used may have to be varied from time to time.

Zinc sulphate

Zinc sulphate does not always intensify the action of the cyanide, the latter often being just as effective by itself ; there are also cases where the former alone gives better results. The most effective reagent or combination can only be found by experiment.

The consumption of sodium cyanide normally ranges from 0.1 to 0.3 lb. per ton of ore and that of ZnSO4.7H2O from 0.3 to 0.9 lb. per ton. These are added to the circuit in the form of solutions containing about 20% of the solid.

Sodium cyanide is occasionally substituted for lime in the flotation of a sulphide copper ore containing pyrite, since it has a much greater depressing effect on the pyrite than on the copper minerals. Xanthate is generally employed to bring up the copper sulphides, its addition being balanced against that of the cyanide to effect a profitable recovery of the copper with the minimum amount of pyrite.

Sodium sulphite was at one time employed as a depressor of sphalerite, its action being much the same as that of cyanide but less effective. Its use is seldom encountered, except in instances where cyanide has been found too powerful

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Florrea depressants can offer a significant economic advanta

Florrea depressants can offer a significant economic advantage in flotation of minerals by increasing grade and recovery of metallic concentrates.

Process Design Experiment

Process Design Experiment


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