FI80835C - FOERFARANDE FOER SELEKTIV ANRIKNING AV KOPPARMOLYBDENMALM. - Google Patents

Abstract

A process for separation of the mineral components of a copper/molybdenum sulfide ore by flotation including (a) crushing and grinding the ore to liberate the minerals; (b) in a primary flotation circuit, adding a molybdenum collector selected from the group of hydrocarbon oils, and a frother; (c) floating a primary (molybdenum) concentrate in the primary circuit in the absence of a copper collector; (d) directing the primary molybdenum concentrate to an upgrading separation circuit to produce a final molybdenum concentrate; and (e) directing the non-float of the primary circuit to a secondary scavenger circuit for recovery of copper and additional molybdenum with addition of a copper collector, the process being conducted at a natural pH essentially determined by the ore composition and the quality of the water used to form the pulp, without addition of substantial amounts of alkaline or acid pH modifiers sufficient to change the pH.

Description

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Method for the selective enrichment of copper molybdenum ore - Förfarande för selektiv anrikning av kopparmolybden-malm

The present invention is directed to an improved process for the selective enrichment of copper molybdenum ore (Mo-Cu) components by foaming. More specifically, the present invention is directed to such an enrichment process carried out at normal pH (e.g., without the addition of alkalis (such as lime) or acids in amounts sufficient to substantially change the pH) and without the addition of a copper collector in the primary flotation cycle. -Cu concentrate recovery.

In conventional copper ore flotation systems, with recoverable molybdenum by-product values, the ore is first crushed and ground, and lime is usually added to press the sulfur fiber. The ore is then treated in a primary flotation cycle after the addition of the copper collector and flotation agent. The coarse copper concentrate thus obtained contains most of the copper and a considerable part of the molybdenum. This coarse copper concentrate is then passed to several purification-flotation steps (usually after the post-grinding step) to produce the finished copper concentrate. This concentrate contains essentially all of the molybdenite recovered in the coarse round. The copper concentrate is then treated with a series of enrichment steps designed to enrich mol-molybdenite, a by-product of several copper ores, into a highly pure concentrate.

The main problem with this system is that, without exception, the lime used may lower the molybdenum content, causing a decrease in the achievable position of the Mo2S mineral.

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Another important problem with conventional systems is that they require molybdenum to be collected from a copper concentrate with a high reagent content. For this reason, the enrichment of molybdenum from copper minerals is particularly difficult. A complex secondary system is required, which is expensive, requires high levels of copper inhibitors, and may result in reduced molybdenum recovery.

It is an object of the present invention to provide a process for enriching copper ore components by flotation (with molybdenum as a by-product). This method provides an effortless, inexpensive, and effective way to take up molybdenum at an acceptable level.

Another object of the present invention is to provide a process for such enrichment which can be carried out at natural pH and which avoids the use of lime and other pH-altering substances.

It is a further object of the present invention to provide a method for such enrichment which avoids the use of substantial amounts of copper mineral inhibitors.

It is a further object of the present invention to provide a method for such enrichment which avoids the use of a copper collector in the primary flotation cycle.

It is a further object of the present invention to achieve, in the primary flotation round, recovery of a concentrate which is substantially enriched in molybdenum and which, due to its increased molybdenum content, can be further enriched to a molybdenum concentrate with less reactants using significantly less refining steps. molybdenum neraal in significantly better recovery. The copper content of this primary flotation round, after the purification steps, can be 3,888,35 to the copper round11e. This does not compromise the overall copper recovery of the system.

These and other objects of the present invention will be apparent to those skilled in the art from this description, the appended claims, and the accompanying drawings.

The present invention relates to a process for the enrichment of mineral components of an ore, said ore consisting of minerals selected from the group consisting of parent metal sulphides, including copper and molybdenum sulphides and pyrite, said process comprising: (a) grinding said ore with water; to form an ore slurry with a suitable particle size distribution for flotation; (b) in primary flotation round 1a, adding a molybdenum collector selected from the group of hydrocarbon oils alongside the flotation agent; (c) in the absence of a copper collector, flotation of the primary copper molybdenum concentrate with said primary concentrate containing a portion of the copper minerals fed to said primary circuit; (d) recovering molybdenum from the primary concentrate in a purification cycle, and directing the rigid flotation bases in a copper cycle; directing the non-foamed portion of said primary round to a secondary copper molybdenum foaming round and performing the art of refined copper concentrate with a small proportion of molybdenite; said process being carried out at a natural pH determined mainly by the composition of the ore and the quality of the water used to form said slurry without adding substantial amounts of temporal or acidic pH variables to alter the pH.

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Figure 1 is an enrichment diagram of a copper molybdenum ore enrichment process by foaming in accordance with the present invention; Figure 2 is a water balance enrichment diagram of a copper molybdenum ore enrichment process commonly used in the southwestern United States where water is scarce.

According to the present invention, the molybdenum-containing copper ore obtained from the mine is crushed and ground to the required particle size to form a flotation feed and ore slurry.

The possible pre-flotation treatment of the ore can be performed during or after the wet comminution step and is stopped before the first flotation step. The pretreatment is indicated by the number 1 in Figure 1. According to the present invention, the only pretreatment that may be required at this stage would require the addition of very small amounts of oxidation-reducing agents, such as sodium sulfide, hydrogen peroxide, etc., or aeration. The combined proportions of mineralization of the ore, the degree of surface oxidation, and the chemistry of the water (unless altered) can result in varying degrees of recovery of copper and iron sulfide minerals alongside molybdenite in the coarser primary molybdenum stage. Pre-foaming treatment of the ore with certain reactants, performed during or after the comminution step, may be necessary to prevent or minimize this recovery of copper and iron sulfides. The reactants used may be reducing in nature, such as hypochlorites, peroxides or atmospheric air. The amounts used are exactly sufficient to prevent or minimize the aforementioned recovery of copper and iron sulfides in addition to molybdenite in the primary molybdenite flotation step. That is, the amount or degree of aeration of the oxidizing-reducing agents is most desirably just sufficient to prevent or minimize the flotation of copper sulfide and pyrite without affecting the flotation of the molybdenite, and the pH is not affected.

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In most cases, no lime or other pH-altering substances are added (or, if added, the lime is in extremely small amounts compared to traditional all-rounds and only for protective alkalinity, e.g. to prevent corrosion of the equipment).

In the primary molybdenite flotation round, a copper collector is not added. However, a small amount of hydrocarbon oil is added as a molar collector, at point 2 in Figure 1, alongside the blowing agent.

Suitable hydrocarbon oils include gas oil, diesel oil, fuel oil, etc. It is desirable that the hydrocarbon contain as little paraffin as possible.

The primary flotation cycle produces a coarse molybdenite concentrate that contains some copper and a non-foamed portion.

This concentrate, the roughness of which is considerably more enriched compared to conventional rounds, is then re-comminuted, if necessary, and led to purification steps leading to the production of a finished molybdenum concentrate. The simplicity and cost savings of the purification step achieved by the present invention are also considerable.

The non-foamed portion of the primary cycle is controlled by a copper foaming cycle. The non-foamed portion includes a portion of copper and other non-foamed minerals. The copper collector is added at point 3 in Figure 1.

Whether or not oxidation-reducing agents are added (either before the primary flotation in step 1 or before the purification step in point 4 in Figure 1) depends to a large extent on the natural oxidation-reduction conditions of the ore and the water used in the flotation process.

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Usually, the coarse copper concentrate is subjected to trace grinding and refining steps, resulting in the production of the finished copper concentrate, the final enrichment origin, and possibly a secondary molybdenum concentrate. This latter concentrate, when produced, represents a small fraction of the total roughness content of the original ore due to the molybdenum recovery efficiency of the primary flotation cycle. This secondary molybdenum concentrate can be recycled to the primary molybdenum cycle or molybdenum purification cycle depending on the molybdenum assay.

Further enrichment of the purified concentrate may require the addition of a small amount of oxidizing-reducing agent sufficient to minimize pyrite flotation.

It is not necessary to use cyanide in the process of the present invention.

It is preferred to use aeration instead of (or in addition to) oxidation-reduction additives to control the oxidation-reduction potential of the slurry. Aeration can be used at point 1 of the primary flotation cycle or at point 4 of the first cleaning cycle.

The advantages of the present process include the simplicity of the flotation scheme and the savings in all reactants, including those due to lime removal and minimal addition of oxidation-reducing agents - if required at all - and also in the consumption of flotation agent and collector.

Other benefits come from the improvement in the recovery and / or degree of noise.

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Suitable molybdenum-copper ores for use in the present process include copper-molybdenum sulfide ores containing copper ore and cast cosite.

The present method is particularly well suited for ore beneficiation in mines where water is recycled. In fact, the present method can well be implemented in enrichment plants where most of the water is recovered as described in Figure 2 (prior art). This is because the addition of reactants (including any collectors and oxidation-reducing agents) is so minimal that they do not accumulate in the recycled water. In Figure 2, about 60% of the water in the system is recovered after flotation of the coarse concentrate 4. Additional water is collected from the cleaning cycle of the non-foamed portion, 2. All recovered water is combined in step 3.

In the following, the invention is further described with reference to certain examples. However, the scope of the present invention is not limited to these examples.

Example 1

Ore: 500 g of copper-moly ore from Kennecott Copper Company’s Chino Mines Division, which contains primarily copper ore.

Water: 350 ml of process H 2 O (from step 1 of Figure 2).

After comminution (ca. 6 min), Na S was added to the slurry (corresponding to 50 g / tonne of ore) in the treatment step (1 min). The slurry was aerated for about 2 minutes with stirring, and then the air was sealed. Fuel oil, 2 drops, was added to the slurry along with 6 drops of MIBC, blowing agent. After coarse concentrate flotation (3 min), 2 drops of copper collector 2694 were added in the treatment step (2 min), and the first purified concentrate was flotated (4 min). A further drop of copper collector (2 min) was then added and the other purified concentrate was foamed. The electrochemical potential was measured and found to be +40 in the first treatment step, during aeration, and in the coarse concentrate flotation step, and +50 in the first purification flotation step. The pH was 7.5 during aeration, 7.8 during treatment, 8.0 during primary concentrate flotation, and 8.2 during secondary concentrate flotation. The results were as follows:

Analysis of Distribution

Product Weight Mo Cu Mo Cu

Coarse concentrate 2.7 0.338 17.75 60.75 34.10 1. pur. rich 3.62 0.032 18.06 9.59 57.89: ·. Primary rich 5.79 0.147 17.94 70.35 91.99

Unfoamed 94.21 0.0038 0.09 29.65 8.01

Estimated input 100.00 0.121 1.129

Example 2

Ore: 500 g of the same copper-moly ore a as in Example 1.

Water 350 ml of process H 2 O (from step 1 of Figure 2).

The ore was comminuted for 6 minutes, and only flotation agent /. (2 drops of MIBC) was added. Fuel oil (6 drops) was added in the first treatment step (1 min), and the slurry was aerated for 2 minutes. Sodium sulfide a or other oxidizing reducing agents were not added. The coarse concentrate was foamed (3 min), and the non-foamed portion was treated (2 min) by adding 2 drops of copper collector. The first purified concentrate was foamed (4 min), and the non-foamed portion was treated for 2 minutes with one additional drop of copper collector (2694), after which the second purified concentrate was foamed.

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Analysis of Distribution

Product Weight Ho Cu Mo Cu

Coarse concentrate 0.72 0.878 8.11 54.36 5.13 1. pur. rich 3.88 0.036 24.42 12.01 83.29

Primary rich 4.60 0.168 21.87 66.37 88.43

Non-foaming 95.40 0.0041 0.138 33.63 11.57

Estimated input 100.00 0.0116 1.137

Claims (9)

A process for separating mineral components from copper-molybdenum ore, the process comprising grinding an ore containing minerals selected from the group consisting of parent metal sulfides, including copper and molybdenum sulfides, and Pyrites, a process for liberating minerals and forming a water mass therefrom, steps: adding to the pulp in the first flotation cycle a blowing agent and a non-ionized molybdenum collector selected from the group of hydrocarbon oils; foaming the first molybdenum concentrate from the pulp in a first round of flotation at a neutral pH substantially determined by said water and ore composition, without the addition of alkaline or acidic pH modifiers; * * directing the first molybdenum concentrate to a further enrichment cycle to produce the final molybdenum concentrate; and directing the non-foamed portion of the first cycle to the purification cycle to recover additional copper and molybdenum. Process according to Claim 1, characterized in that the naturally foamable copper sulphides and pyrites are reduced in the pulp by subjecting the pulp to aeration in the first flotation cycle. A method according to claim 1, characterized in that a collector is added to the non-foamed part of the first foaming cycle. A method according to claim 1, characterized in that an oxidizing or reducing agent is added to the non-foamed part of the cleaning cycle. 80835 11 A method according to claim 4, characterized in that the non-foamed part of the first flotation round is exposed to aeration after the addition of an oxidizing or reducing agent. A method according to claim 1, characterized in that the step of foaming the non-foamed part of the first flotation cycle is carried out in a cleaning cycle at a neutral pH substantially determined by said water and the composition of the non-foaming part, without the addition of an alkaline or acidic pH modifier. A method according to claim 1, characterized in that no pH modifier is added to the ore during its grinding steps, during the molybdenum collector and blowing agent addition step, or during the flotation of the pulp in the first flotation round. The method of claim 1, further comprising the steps of: performing a second treatment on the non-foamed portion of the first flotation cycle by adding a copper collector to the non-foamed portion; foaming the detergent concentrate from the non-foamed portion that has undergone the second treatment to recover additional copper and molybdenum; and recovering additional molybdenum and final copper concentrate from the detergent concentrate and purification residues from the enrichment separation cycle. Process according to Claim 8, characterized in that an oxidizing or reducing agent is added to the pulp in the second treatment step. 12 80835