Two-stage flotation process for low-grade mixed potassium salt

Abstract

The invention discloses a two-stage flotation process for low-grade mixed potassium salt. The process comprises the following steps: (1) grinding low-grade mixed potassium salt until content of the salt with size fraction of -0.15mm is no less than 64.90% by mass; (2) transferring ore pulp obtained from the step (1) to a flotation machine for the first stage of flotation; (3) adding an anionic collector to coarse ore pulp obtained from the step (2) for the second stage of flotation; (4) totally combining potassium chloride concentrate obtained from the step (2) with the second stage of flotation concentrate obtained from the step (3), adding fresh water at a mass ratio of the concentrate to the fresh water of 1: (0.65-0.80), stirring at normal temperature and conducting a conversion reaction fore 1-2h, filtering and drying to obtain a finished potassium sulfate fertilizer product. The process disclosed by the invention has such advantages as simple process, low energy consumption, easy implementation of operation and high K<+> recovery rate, and is suitable for recovering a potassium resource from some low-grade mixed potassium salt complex in potassium mineral composition through flotation.

Description

technical field [0001] The invention belongs to the field of potassium salt flotation, and relates to a process for preparing potassium and magnesium fertilizers by using low-grade potassium mixed salt flotation, in particular to a process for preparing potassium and magnesium fertilizers by using low-grade potassium mixed salts to flotation potassium salt minerals in stages Two-stage flotation process. Background technique [0002] Potassium-containing minerals mainly include potassium halite, carnallite, langbeinite, kaleolite, polyhalite, etc., and the potassium mixed salt mines obtained by drying the existing sulfate-type salt lake brine generally contain lentilite Magnesite (K 2 SO 4 · MgSO 4 ·6H 2 O), potassium chloride, Epsom salts (MgSO 4 ·7H 2 O) and sodium chloride, while potassium chloride and epsom salt will be partially converted into kainite (KCl MgSO 4 2.75H 2 O), if the temperature is higher again, kobeinite may also be converted into kobeinite (K 2 ...

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Problems solved by technology

[0002] Potassium-containing minerals mainly include potassium halite, carnallite, langbeinite, kaleolite, polyhalite, etc., and the potassium mixed salt mines obtained by drying the existing sulfate-type salt lake brine generally contain lentilite Magnesite (K 2 SO 4 · MgSO 4 ·6H 2 O), potassium chloride, Epsom salts (MgSO 4 ·7H 2 O) and sodium chloride, while potassium chloride and epsom salt will be partially converted into kainite (KCl MgSO 4 2.75H 2 O), if the temperature is higher again, kobeinite may also be converted into kobeinite (K 2 SO 4 · MgSO 4 4H 2 O) or langbeinite (K 2 SO 4 2MgSO 4 ), therefore, if the potassium mixed salt ore obtained after the sulfate-type salt lake brine is sun-dried is not sent to the flotation workshop in time for flotation to extract magnesite or potassium chloride but is placed aside for a long time, it is easy to make potassium mixed The ore properties of salt mines, especially the mineral forms of potassium salt minerals, have changed greatly, which has brought great difficulties to the flotation separation of potassium mixed salts

[0003] At present, the potassium mixed salt obtained by using sulfate-type brine after drying in the salt field is usually directly sent to the flotation workshop for flotation. The potassium minerals in the raw ore of the potassium mixed salt are relatively simple, only langbeinite and potassium chloride , generally add fresh water to convert all potassium chloride into langbeinite and then carry out flotation, which is commonly referred to as "conversion first and then flotation". more, this tends to lose some K + Recovery rate

However, sometimes the workshop is under maintenance or renovation, or the processing capacity of the workshop cannot meet the ore output of the salt field potash mixed salt ore, and the excess potassium mixed salt mine needs to be temporarily piled up in a designated place. Part of the langbeinite in the salt is easy to turn into langbeinite and anhydrous langbeinite, and even potassium chloride and epsomium salt are also easy to turn into langbeinite. At this time, it is necessary to process this kind of potassium mixed salt. Of course, it can be used The flotation process after the above-mentioned first conversion, but because the effect of sodium dodecylsulfonate flotation langbeinite and anhydrous langbeinite is not very good, the K of flotation tailings loss + The recovery rate will be higher

In the existing patent documents or academic journals and other public materials, no reports have been found on the use of two-stage flotation process flotation to treat the potassium mixed salt mines that have been piled up for a long time after being spread in the salt field, nor have they been found to use 3-hexadecyloxy Propylamine hydrochloride flotation Potassium chloride or kainite and C 12 ~C 16 A report on the flotation of langbeinite with a mixture of sodium alkylsulfonates

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