KR910003051B1 - Frother composition - Google Patents

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Description

Process for beneficiation of nonmetal sulfide minerals from nonmetal sulfide ores and catcher for foam flotation

The present invention relates to a foam flotation method for recovering useful metals from metal sulfide ores.

More specifically, the present invention relates to novel and improved sulfide collectors comprising hydrocarboxycarbonyl thionocarbamate compounds or hydrocarboxy carbonyl thiourea compounds. It shows excellent metallurgical performance over the value.

Foam flotation is one of the most widely used methods for beneficiation associated with useful minerals. This method is particularly used to separate the finely divided useful minerals from their associated gangue or to separate the useful minerals from each other. This method is based on the affinity for bubbles of properly prepared mineral surfaces. In foam flotation, foam or foam is formed by introducing air into a stirred flounder of finely pulverized ore into water containing a foaming agent or foaming agent. The main advantage of foam flotation is that it operates relatively effectively at a significantly lower cost than many other methods.

Current theories and methods describe that the success of sulfide flotation depends largely on reagents called catchers, which are selective for useful sulfide minerals that must be separated from other minerals. Impart hydrophobicity. Thus, flotation of one mineral species from another mineral species depends on the relative wettability of the mineral surface to water. Typically free surface energy is lowered by adsorption of this hetero polar collector. It can be explained that the hydrophobic coating thus provided acts as a bridge to allow mineral particles to adhere to the bubbles. However, the practice of the present invention is not limited to these or other theories of flotation.

In addition to catchers, several other reagents are also needed. Among these, the use of a foaming agent provides a stable flotation which lasts long enough to promote mineral beneficiation but which does not interfere with the next process. The most commonly used foaming agents are pine oil, creosote, cresyl acid, and alcohols such as 4-methyl-2-pentanol, polypropylene glycol, ethers and the like.

Moreover, any other important reagents, such as modifiers, also greatly influence the success of flotation of sulfide minerals. Modulators are all reagents that control the mineral surface to prevent or prevent the catcher from adsorbing the mineral surface, whose main function is not catchment or foaming. Thus, modulators are inhibitors, active agents, pH adjusters, dispersants, inactive agents and the like. Sometimes a regulator can perform several functions simultaneously. Current theories and methods for sulfide flotation have described that the efficiency of all classes of flotation agents depends largely on the degree of acidity or alkalinity of the flounder. After all, a regulator to adjust the pH is very important.

The most commonly used pH adjusters are lime, soda ash, and caustic soda with less frequent use. However, in sulfide flotation, lime is by far the most widely used. In flotation of copper sulfide, which is the mainstream of the sulfide flotation industry, for example, lime is used to maintain a pH value of at least 10.5, more typically at least 11.0, and sometimes at about 12 or 12.5. In the conventional sulfide flotation method, the preliminary adjustment of the pH of the photonic slurry to 11.0 or more not only inhibits harmful iron gangue sulfide minerals such as pyrite and pyrrhotite, but also xanthate and dity. There is a need for improving the performance of the majority of conventional sulfide catchers such as phosphate, trithiocarbonate, thionocarbamate. However, because the costs associated with adding lime are so great, plant operators may need to perform flotation, which requires little or no addition of lime, for example, flotation that can be efficiently performed at slightly alkaline, neutral or even acidic pH values. Interested in beneficiation. In particular, neutral and circuit flotation is required because the photonicsery can be easily acidified by the addition of sulfuric acid and sulfuric acid is obtained as a by-product of melters in many plants. Therefore, flotation, which does not require preliminary adjustment of the pH or preliminarily adjusts the pH to a neutral or acidic pH value using cheaper sulfuric acid, is more desirable than current flotation, because current methods are costly. This is because more lime is required to pre-adjust the pH to an alkali value of at least about 11.0.

A better indication of the current problem is that in 1980, the amount of lime used in the copper and molybdenum mining sector in the United States was nearly £ 550 million. In this industry, lime accounted for nearly 92.5 wt.% Of the total reagent used, the dollar value of lime used was about 51.4% of the total reagent cost in this industry, totaling about $ 28 million It was.

As mentioned above, lime consumption in individual plants varies from about 11 b. (Lime) / metric ton (treated ore) to 201 b. (Lime) / metric ton (ore). In certain geographic regions, such as South America, lime is a rare commodity and the cost of transporting and / or importing lime has increased significantly in recent years. Another problem with the high alkaline methods of the prior art is that the addition of large amounts of lime to obtain a sufficiently high pH results in the formation of scales on the plant and flotation equipment, which often necessitates frequent and costly downtime to clean them.

It is therefore clear that sulfide flotation requires a significant reduction in the cost of reagents by reducing or eliminating the need for lime addition. In addition, eliminating the use of lime in sulphide ore treatment may provide other benefits by facilitating the operation and implementation of unit operations other than flotation, such as slurry treatment.

In the past, xanthates and dithiophosphates have been used as sulfide catchers in foam flotation of nonmetal sulfide ores. The main problem with this conventional sulfide catcher is that the rejection of iron sulfide and pyrrhotite is poor at pH values below 11.0. In addition, as the pH decreases, the catching power of these sulfide catchers also decreases, thus the catchers are not suitable for flotation in a weakly alkaline, neutral or acidic environment. If the catchment force is thus reduced as the pH is reduced to, for example, about 11.0 or less, the amount of catcher used must be multiplied, which is usually uneconomical. There are many factors that can explain the drop in catcher activity due to a decrease in pH. A catcher may interact differently with other sulfide minerals at a given pH. On the other hand, poor solution stability at low pH, such as that shown by xanthate and trithiocarbonate, well illustrates the behavior of the weak catcher.

으로 나타내는 알킬크산토겐알킬포르메이트와 같은 크산테이트의 중성 유도체의 개발을 가져왔다. 알킬 크산토겐 알킬포르메이트는 미합중국 특허 제 2,412,500호에 황화물 포수제로서 기술되어 있다. 상기 일반 구조에 대한 다른 구조적 변경은 후에 발표되었다. 예를들면 미합중국 특허 제 2,608,572호에서, 알킬 포르메이트 치환체는 불포화기를 함유한다. 미합중국 특허 제 2,608,573호에서, 기술된 알킬 포르메이트 치환체는 할로겐, 니트릴, 니트로기를 포함한다. 비스 알킬크산토겐 포르메이트는 미합중국 특허 제 2,602,814호에 황화물 포수제로서 기술되어 있다. 이러한 변경된 구조들은 변경되지 않은 구조와 마찬가지로 상업적으로 많이 사용되지 못하였다. 예를 들면 현재 알킬 크산토겐 알킬 포르메이트는 미네렉 코포레어션사의 상표면 MINERAC A로서 상업적으로 이용가능하다. 그보다 더 가까운 동류체는 물론 에틸 크산토겐 에틸포르메이트인 MINERAC A는 11.0 이하의 pH에서 부족한 점이 많은데, 이는 본 명세서에서 더욱 구체적으로 후술하는 바와같이, 황화철광의 거부와 포수력의 면에서 그러하다.Efforts to overcome the deficiencies described above are generally

It has led to the development of neutral derivatives of xanthate such as alkylxanthogenalkylformates. Alkyl xanthogen alkylformates are described in US Pat. No. 2,412,500 as sulfide catchers. Other structural changes to the general structure were later published. For example, in US Pat. No. 2,608,572, alkyl formate substituents contain unsaturated groups. In US Pat. No. 2,608,573, the alkyl formate substituents described include halogen, nitrile, nitro groups. Bis alkylxanthogen formate is described in US Pat. No. 2,602,814 as a sulfide catcher. Such altered structures were not used as much commercially as unaltered structures. For example, currently alkyl xanthogen alkyl formate is commercially available as MINERAC A under the trade name of Minerek Corporation. MINERAC A, an ethyl xanthogen ethylformate, as well as a closer homologue than that, is lacking at pH below 11.0, as described in more detail herein below, in terms of rejection and catchment of iron sulfide. .

Another class of sulfide catchers that can achieve some commercial success in foam flotation are oily sulfide catchers comprising dialkyl thionocarbamates or diurethane compounds represented by the following general formula:

There are several disadvantages associated with making and using such compounds. US Pat. No. 2,691,635 describes a process for preparing dialkylthionocarbamate. The three-step reaction sequence described is inconvenient and the final byproduct is methyl mercaptan, one of the air pollutants that is expensive to treat. US Patent No. 3,907,854 describes an improved process for preparing dialkylthionocarbamate. The novel features of the invention claim good yield and high purity, but it is noteworthy that the by-products of the reaction are sodium hydrogen sulfide, a pollutant that requires special treatment to remove. U. S. Patent No. 3,590, 998 describes a thionocarbamate sulfide catcher structure wherein the N-alkyl substituent is linked by an alkoxycarbonyl group. The production method described in this patent specification requires the use of expensive amino acid esters for the substitution reaction of xanthate to thioesters. By-products of this process are methyl mercaptan or sodium thioglycolate. Moreover, this type of structurally modified thionocarbamate has had little commercial success. As apparent from the specification of the present invention described below, dialkylthionocarbamate is a weak catcher when the pH drops below a certain value.

It is therefore an object of the present invention to provide a novel and improved flotation and sulfide catcher for beneficiation of sulfide minerals using a foam flotation method which does not require an arbitrary preconditioning of the pH to an alkali value.

It is another object of the present invention to provide new and improved foam flotation and sulfide catchers for beneficiation of sulfide minerals which selectively recover useful metal sulfides and selectively reject iron sulfides, pyrophoric iron and other gangue sulfides. It is.

Another object of the present invention is to provide a novel process for beneficiation of sulfide minerals using foam flotation using a novel class of sulfide catcher reagents that can be prepared and used without forming harmful by-products or environmental pollutants. To provide improved flotation and sulfide catchers.

Another object of the present invention is to beneficiate sulfide ores at a pH value of 10.0 or less using certain novel catchers containing novel donor atom compounds specifically designed for low pH flotation. It is to provide flotation.

It is yet another object of the present invention to provide a novel and improved process for the selective flotation of sulphide, which is useful in acidic circuits for controlling pH using inexpensive sulfuric acid.

In accordance with these and other objects, the present invention specifically provides a novel and improved catcher composition for beneficiation of ore containing sulfide minerals while rejecting iron sulfide, magnetite and other gangue sulfides. The composition comprises at least one hydrocarboxycarbonylthioo carbamate compound selected from compounds represented by the formula:

Wherein R ¹ and R ² are each independently selected from saturated and unsaturated hydrocarbyradicals, alkylpolyetherradicals and aromatic radicals, which radicals are optionally and independently substituted with polar groups selected from halogen, nitrile and nitro groups. Particularly preferred hydrocarboxycarbonyl thionocarmate sulfide catchers according to the invention are compounds having the above formula wherein R ₁ is C ₁ -C ₆ alkyl or aryl and R ₂ is C ₁ -C ₈ alkyl.

In general, and without limitation, the novel and improved hydrocarboxycarbonyl thionocarbamate catcher of the present invention effectively screens valuable minerals and metals from nonmetal sulfide ores, while rejecting iron sulfide and other gangue sulfides. To about 0.005-0.5 pounds per tonne (ore), preferably about 0.01-0.1 pounds per tonne (ore). The novel and improved sulfide catchers of the present invention can generally be used regardless of the pH of the sludge slurry. In other words, without any limitation, such catcher may be used at a pH value of about 3.5-11.0, preferably at a pH value of about 4.0-10.0.

In another embodiment, the present invention provides a novel and improved method for screening ore sulphide and pyrrhotite ores for beneficiation of ores containing sulphide minerals, the method comprising polishing the ore to increase the flotation size. Particles, slurry the particles in an aqueous medium, condition the slurry with an effective amount of foaming agent and metal catcher, and give preference to sulfide minerals as desired over gangue sulfide minerals by foam flotation procedures. Consisting of causing foam; The metal catcher comprises at least one hydrocarboxycarbonyl thionocarbamate compound selected from compounds having the formula given above.

In a particularly preferred embodiment, a novel and improved method for improving the recovery of copper sulfide minerals from ores containing various sulfide minerals is provided, wherein flotation is performed at controlled pH values of 10.0 or less or equivalent , The catcher is added to the flotation cell.

According to another embodiment, the present invention provides a novel and improved catcher composition capable of screening rejection of iron sulfide and other gangue sulfides or non-sulfides and beneficiation of ores containing sulfide minerals. The composition comprises at least one hydrocarboxycarbonyl thiourea compound selected from compounds represented by the formula:

Wherein R ¹ is hydrogen or R ² ; R ² is selected from saturated and unsaturated hydrocarbyradicals, hydrocarboxy radicals and aromatic radicals; R ³ is selected from saturated and unsaturated hydrocarbyradicals, alkyl polyetherradicals and aromatic radicals, wherein the R ² and R ³ radicals are optionally and independently substituted with polar graps selected from halogen, nitrile and nitro groups do. Particularly preferred hydrocarboxycarbonyl thiourea sulfide catchers used in the process of the invention are those in which R ¹ is hydrogen or C ¹ -C ⁶ alkyl; R ² is C ₁ -C ₈ alkyl, allyl, alkaryl or aryl; R ³ is C ₁ -C ₆ alkyl or aryl.

In general and without limitation, the novel and improved hydrocarboxycarbonyl thiourea catcher of the present invention is capable of effectively screening and recovering useful metals and minerals from non-metal sulfide ores while screening and rejecting iron sulfide and other gangue sulfides or non-sulfides. It is used in an amount of about 0.005-0.5 pounds / ton (ore), preferably about 0.01-0.3 pounds / ton (ore). The novel and improved sulfide catchers of the present invention can generally be used irrespective of the pH value of the photonic slurry. The novel and improved sulfide catchers of the present invention can generally be used irrespective of the pH value of the photonic slurry. In other words, without limitation, these catchers can be used at a pH value of about 3.5-11.0, preferably at a pH value of about 4.0-10.0.

In another embodiment, the present invention provides a new and improved method for screening ore sulphide and other gangue sulfides or non-sulfides and beneficiating ores containing sulphide minerals, the method crushing the ore Into particles of flotation size, slurries the particles in an aqueous medium, adjusts the slurry with an effective amount of foaming agent and metal catcher, and uses foam flotation procedures to give better results than iron sulfide and other gangue sulfides or non-sulfides. Consisting primarily of foaming the desired sulfide mineral; The metal catcher comprises at least one hydrocarboxy carbonyl thiourea compound selected from compounds having the formula given above.

In a particularly preferred embodiment, a new and improved method of improving the recovery of copper from ores containing various copper sulfide minerals is provided, wherein flotation is carried out at a controlled pH value of 10.0 or less. The catcher is added to the flotation cell.

Accordingly, the present invention relates to the provision of a novel sulfide catcher for foam flotation of nonmetal sulfide ores and a method for improving the same. The process of the present invention and the hydrocarboxycarbonyl thionocarbamate catcher unexpectedly showed better metallurgical recovery than in foam flotation, even with a lower amount of catcher compared to conventional sulfide catchers. Effective even under acidic, neutral or mildly alkaline pH conditions. According to the present invention, there is provided a sulfide ore foam flotation method which considerably reduces the consumption of lime and at the same time provides better refining of useful sulfide minerals.

Other objects and advantages of the present invention will become apparent from the following description and exemplary embodiments.

According to the present invention, useful metal sulfides and minerals are recovered by foam flotation in the presence of a novel sulfide catcher, the catcher comprising at least one hydrocarboxycarbonyl thionocarbamate compound represented by the following formula: Include.

Wherein R ¹ and R ² are independently selected from saturated and unsaturated hydrocarbyradicals, alkylpolyetherradicals and aromatic radicals, wherein the R ¹ and R ² radicals are optionally and independently from halogen, nitrile, nitro groups It may be substituted by a selected polar group. Hydrocarbyl refers to radicals constituting hydrogen and carbon atoms, including straight or branched, saturated or unsaturated, cyclic or acyclic hydrocarbon radicals. The R ¹ and R ² radicals may be unsubstituted or optionally substituted by polar groups such as halogen, nitrile or nitro groups. In addition, R ¹ and R ² can be independently selected from alkyl polyether radicals of the formula:

R ³ (OY) _n-

Wherein R ³ is C ₁ -C ₆ alkyl; Y is an ethylene or propylene group and n is an integer from 1 to 4 (including 4). R ¹ and R ² are also aromatic radicals such as benzyl, phenyl, cresyl and xylenyl radicals, aralkyl or alkaryl radicals, or any such aromatic radicals optionally substituted by the aforementioned polar groups. Can be selected from.

In a preferred embodiment, the hydrocarboxycarbonyl thionocarbamate catcher of the above formula used is selected from R ¹ is C ₁ -C ₆ alkyl, or aryl, particularly preferably ethyl, isopropyl, or phenyl radicals. Become; R ² is a C ₁ -C ₈ alkyl radical such as methyl, ethyl, n-propyl, isopropyl, n-butyl, secondary-butyl, isobutyl, n-amyl, isoamyl, n-hexyl, isohexyl , Heptyl, n-octyl, 2-ethylhexyl.

Examples of compounds within the range of the above formula for use as sulfide catchers in accordance with the present invention include:

N-ethoxycarbonyl-O-methyl thionocarbamate, N-ethoxycarbonyl-O-ethylthionocarbamate, N-ethoxycarbonyl-O- (n-propyl) thionocarba Mate, N-ethoxycarbonyl-O-isobutyl thionocarbamate, N-ethoxycarbonyl-O- (n-pentyl) thionocarbamate, N-ethoxycarbonyl-O- (2 -Methylpentyl) thionocarbamate, N-ethoxycarbonyl-O-allyl thionocarbamate, N-ethoxycarbonyl-O- (2-methoxy ethyl) thionocarbamate, N- Ethoxycarbonyl-O- (2-ethoxyethyl) thionocarbamate, N-ethoxycarbonyl-O- (2-butoxyethyl) thionocarbamate, N-propoxycarbonyl-O -Propyl thionocarbamate, N-phenoxycarbonyl-O-ethyl thionocarbamate, and N-phenoxycarbonyl-O-isopropyl thionocarbamate.

The hydrocarboxycarbonyl thionocarbamate compounds of the present invention can be conveniently prepared without forming contaminating byproducts, by first reacting the corresponding chloroformate compound with ammonium, sodium or potassium thiocyanate The isothiocyanate intermediate is formed according to Scheme 1 below:

Wherein R ¹ is the same as defined above and X is NH ₄ ⁺ , Na ⁺ , or K ⁺ .

Thereafter, the hydrocarboxycarbonyl isothiocyanate intermediate is reacted with the active hydroxyl compound according to the following scheme (2):

By active hydroxyl compound is meant any compound containing a hydroxyl group that readily reacts with isothiocyanate to form the corresponding thionocarbamate. Exemplary active hydroxyl compounds include aliphatic alcohols which are cyclic and acyclic, saturated and unsaturated, unsubstituted or substituted by polar groups such as chloro, bromo, iodine, halogen, nitrile and nitro groups; Aryl alkanols such as benzyl alcohol; Ethoxylated and / or propoxylated alcohols and phenols.

Corresponding chloroformates for reacting with ammonium, sodium or potassium thiocyanate according to Scheme 1 above can be prepared by reacting the corresponding aliphatic or aromatic alcohols with phosgene according to Scheme 3 below:

Wherein R ⁴ is composed of any active hydroxyl compound as defined above. For further explanation, chloroformates prepared from ethoxylated or propoxylated alcohols are used in the process, i.e.

And R ⁵ is C ₁ -C ₆ alkyl and n is 1-4 (including 4); At the same time chloroformates made from aromatic alcohols such as phenol, cresol and xylenol,

And R ⁶ = H or CH _3, wherein R ⁷ = H, CH ₃ , Cl, Br, I, -NO ₂ or -C = N.

Referring again to the preparation of the novel and improved hydrocarboxycarbonyl thionocarbamate sulfide catcher of the present invention shown in Schemes (1) and (2) above, the sodium chloride in the reaction of Scheme (1) It is obvious that it is a harmless byproduct. Moreover, in Scheme (2), the condensation of the active hydroxyl compound with isothiocyanate is fast and complete and does not release any contaminant by-products.

Optionally, according to the present invention, useful metal sulfides and minerals are recovered by foam flotation in the presence of a novel sulfide catcher, wherein the catcher comprises at least one hydrocarboxycarbonyl thiourea compound of the formula :

Wherein R ¹ is hydrogen or R ² ; R ² is selected from saturated and unsaturated hydrocarbyradicals, hydrocarboxyradicals and aromatic radicals; R ³ is selected from saturated and unsaturated hydrocarbyradicals, alkyl polyetherradicals and aromatic radicals, wherein the R ² and R ³ radicals are optionally and independently substituted by polar groups selected from halogen, nitrile, nitro groups. Hydrocarbyl means a radical consisting of carbon atoms and hydrogen, including straight or branched, saturated or unsaturated cyclic or acyclic hydrocarbon radicals. The R ² and R ³ radicals may be unsubstituted or optionally substituted by polar groups such as halogen, nitrile and nitro groups. In addition, R ² and R ³ can be independently selected from alkyl polyether radicals of the formula:

R ₄ (OT) ^n-

Wherein R ⁴ is C ₁ -C ₆ alkyl; Y is an ethylene or propylene group, n is an integer of 1-4 (inclusive). R ² and R ^{3 may} also be independently selected from aromatic radicals such as benzyl, phenyl, cresyl and xylenyl radicals and any such aromatic radicals which are optionally substituted by an alkyl or alkaryl radical or a polar group as described above. Can be.

In a preferred embodiment of the process of the invention, the hydrocarboxycarbonyl thiourea catcher of the above formula used is wherein R ¹ is hydrogen and R ² is for example methyl, ethyl, n-propyl, isopropyl, n C ₁ -C ₈ alkyl radicals which are —butyl, secondary butyl, isobutyl, n-amyl, isoamyl, n-hexyl, isohexyl, heptyl, n-oxyl, 2-ethylhexyl, or for example phenyltolyl And aryl radicals which are xylyl; R ³ is a compound selected from C ₁ -C ₆ alkyl or aryl.

Examples of compounds within the range of the above formula for use as sulfide catchers according to the invention include:

N-ethoxycarbonyl-N'-isopropyl thiourea; N-ethoxycarbonyl-N'-isobutyl thiourea; N-ethoxycarbonyl-N ', N'-methylisopropyl thiourea; N-ethoxycarbonyl-N'-allyl thiourea; N-propoxycarbonyl-N'-phenyl thiourea; N-phenoxycarbonyl-N'-isopropyl thiourea; N'-ethoxycarbonyl-N'-tolyl thiourea; N'-phenoxycarbonyl-N'-allyl thiourea; And N-phenoxycarbonyl-N'-cyclohexyl thiourea.

Hydrocarboxycarbonyl thiourea compounds for use in the flotation process of the present invention can be prepared without forming contaminating byproducts, first reacting the corresponding chloroformate compound with ammonium, sodium or potassium thiocyanate To form an isothiocyanate intermediate product according to the following scheme (1).

Wherein R ³ is the same as defined above and X is NH ₄ ⁺ , Na ⁺ , or K ⁺ .

Thereafter, the hydrocarboxycarbonyl isothiocyanate intermediate is reacted with the active amine compound according to the following scheme (2):

By active amine compound is meant any amine compound that readily reacts with isothiocyanate to form the corresponding thiourea. Exemplary active amine compounds include cyclic and acyclic, saturated and unsaturated, aliphatic amines which are unsubstituted or substituted by polar groups such as halogens such as chloro, bromo, iodine, nitriles and nitro groups; Aromatic amines such as aniline, toluidine, xylidine, benzylamine, alkoxy or aryl oxyamine; Etheramines and ethoxylated and / or propoxylated amine anilines.

Corresponding chloroformates for the reaction with ammonium, sodium or potassium thiocyanate according to Scheme 1 above can be prepared by reacting the corresponding aliphatic or aromatic alcohols with phosgene according to Scheme 3 below:

Wherein R ³ OH is an active hydroxyl compound. By active hydroxyl compound is meant any compound containing hydroxyl groups that readily react with phosgene to form the corresponding chloroformate material. Exemplary active hydroxyl compounds include cyclic and acyclic, saturated and unsaturated, aliphatic alcohols which are unsubstituted or substituted by polar groups such as chloro, bromo, or iodine, such as halogens, nitriles and nitro groups; Aromatic alcohols such as phenol and xylenol; Arylalkanols such as benzyl alcohol; And ethoxylated and propoxylated alcohols.

More specifically, chloroformate prepared from ethoxylated or propoxylated alcohols can be used in the present method, i.e.

According to the invention, wherein R ⁵ is C ₁ -C ₆ alkyl and n is 1-4 inclusive; Likewise, chloroformates prepared from aromatic alcohols such as phenol, cresol and xylenol

And R ⁶ is H or CH ₃ and R ⁷ is H, CH ₃ , Cl, Br, I, -NO ₂ or -C≡N.

Referring again to the preparation of the novel and improved hydrocarboxycarbonyl thiourea sulfide catchers of the present invention shown in Schemes (1) and (2) above, sodium chloride is the only harmless by-product in the reaction of Scheme (1). It is obvious. Furthermore, in Scheme (2), the condensation of the active amine compound with isothiocyanate is fast and complete and does not emit any pollutant by-products.

In accordance with the present invention, the aforementioned hydrocarboxycarbonyl thionocarbamates and thioureas are sulfide minerals useful from nonmetal sulfide ores over a wide range of pH values, more specifically under acidic, neutral, weakly alkaline and strongly alkaline conditions. It is used as a sulfide catcher in new and improved foam flotation methods which provide an improved method of beneficiation.

According to the present invention, a novel and improved, essentially pH-independent method for beneficiation of useful minerals from non-metal sulfide ores consists of first preparing ore particles of flotation size by reducing the size of the ore. As will be apparent to those skilled in the art, the particle size, ie, the glass size, to which the size of the ore should be reduced in order to release the useful minerals from the associated gangue or useless minerals depends on the ore, and various factors, for example For example, it may depend on factors such as the geometry of the mineral deposits in the ore, ie stripes, agglomeration, comatrices. In any case customary in the art, the measurements that follow as the particles shrink to the glass size can be made by microscopic examination. In general and without limitation, suitable particle sizes vary from about 50 mesh to about 400 mesh. Preferably the ore is reduced in size to suspended beneficiation particle size between about +65 mesh and about -200 mesh. Particularly preferred for use in the process of the invention are nonmetallic metal sulfides in size to provide about 14-30 wt.% +100 mesh particles and about 45-75 wt.% -200 mesh size particles.

The size velocity of the ore can be carried out according to any method known to those skilled in the art. For example, the ore may be crushed to a -10 mesh size and then wet polished to a specific mesh size in a steel ball mill, or autogenous or semi-autogenous polishing or pebble milling may be used. As long as an effective flotation size particle is provided, the procedure used to downsize the ore is not very important in the method of the present invention.

Preliminary adjustment of the pH can be conveniently performed by adding a control system during the polishing of the reduction step.

The pH of the sludge slurry can be adjusted to any desired value by adding acid or base, typically sulfuric acid or lime, respectively, is used for this purpose. A distinct advantage of the process is that the novel and improved hydrocarboxycarbonyl thionocarbamates and thiourea sulfide catchers used in the process of the present invention do not require any preconditioning of the pH and generally have a flotation neutral pH. This can be done in the light of the process, which simplifies the method, reduces costs, reduces lime consumption and associated downtime. Thus, for example, according to the method of the present invention it can be well beneficiated at a pH value in the range of 3.5-11.0, in particular at a pH value in the range of about 4.0 to about 10.0.

For example, the scaled ore comprising glass-sized particles is then slurried in an aqueous medium to produce suspended sludge. The flocculation or aqueous slurry of flotation size ore particles is typically from about 10-60 wt% of the flocculation solids, preferably from about 25-50 wt.%, Particularly preferably from about 30-40 wt.% It is adjusted to provide an optical needle slurry containing an optical needle solid.

According to a preferred embodiment of the process of the invention, flotation of copper, zinc and lead sulfides is carried out at a pH value of 10.0 or less, preferably 10.0 or less. When flotation at these pH values, the novel and improved hydrocarboxycarbonyl thionocarbamates and thiourea catchers of the present invention are exceptionally good catchers with good catcher selectivity, even with reduced use of catchers. It was found that the strength was shown. Thus, in this preferred method, the sulfuric acid is used to bring the pH of the photonic slurry to 10.0 or less, if necessary.

In any case and for any reason, the pH of the photonicsler can be preadjusted, if necessary, by any method known to those skilled in the art.

After the optical needle slurry is prepared, the slurry is controlled by adding an effective amount of a catcher and a foaming agent including at least one hydrocarboxycarbonyl thionocarbamate compound or at least one hydrocarboxycarbonyl thiourea compound described above. By "effective amount" is meant any amount of each of the components that provides the desired level of beneficiation for the desired useful metal.

More specifically, any known foaming agent can be used in the method of the present invention. More specifically, foaming agents such as straight or branched chain low molecular weight hydrocarbon alcohols such as C ₆ -C ₈ alkanols, 2-ethylhexaol and 4-methyl-2-pentanol, methyl isobutyl carbinol (MIBC) Pine oil, cresylic acid, polyglycol or polyglycol may be used as well, and monoether and alcohol ethoxylate may be used, which only lists some foaming agents which may be used as foaming agents herein. Generally and without limitation, foaming agents are added in conventional amounts, for example about 0.01 to about 0.2 pounds of foaming agent per tonne of treated ore are suitably used.

New and improved hydrocarboxy carbonyl thionocarbamate sulfide scavenger for use in the process of the present invention may generally be added in an amount of about 0.005-0.5 pounds (catcher) / ton (ore), preferably Preferably in an amount of about 0.01-0.3 pounds / tonne (treated ore).

In flotation, which requires screening and catching copper sulfide minerals and screening rejection of iron sulfide minerals such as iron sulfide and pyrite, together with other gangue sulfides, the catcher is generally from about 0.01 to about 0.1 pounds / ton May be added in an amount of). In bulk sulfide flotations, higher amounts of catcher will be used, as described in more detail below.

New and improved hydrocarboxycarbonyl thiourea sulfide catchers for use in the process of the present invention may generally be added in an amount of about 0.005- about 0.5 pounds (catcher / tonne ore), preferably about Will be added in an amount of 0.01-about 0.3 pounds (treated ore). For flotation where iron sulfide and other gangue sulfides are selectively inhibited relative to copper sulfide, the amount of catcher used will generally be between 0.01-0.05 pounds / ton.

Then, according to the method of the present invention, a controlled slurry containing an effective amount of catcher and an effective amount of foaming agent comprising at least one hydrocarboxycarbonyl thionocarbamate or thiourea compound is subjected to conventional foam flotation. As a result, the foaming step allows the desired sulfide minerals to be suspended in the foam concentrate and to reject or inhibit the iron sulfide and other gangue sulfides.

Surprisingly, contrary to the conventional idea that neutral, oil-based catchers are most effective when added to grinding instead of flotation cells, the novel and improved hydrocarboxycarbonyl thionocarbamates and thio of the present invention It has been found that urea catcher shows a more efficient recovery when added to the flotation cell than a grinder. The novel catcher of the present invention has the significant advantage that although it is in fact insoluble in water, it is easily dispersed. When added to the flotation cell, the new catcher significantly improved the recovery of copper in the first stage flotation with the improvement of the overall copper recovery, indicating an improvement in the kinetics of the flotation. This will be described later in this specification more fully. Of course, new and improved catchers may also be added to the grinder according to conventional methods to significantly improve the recovery of useful minerals.

The novel and improved hydrocarboxycarbonyl thionocarbomates and titourea catchers of the present invention and methods of combining them up to now have been particularly useful for certain useful metalsulfides which are copper, nickel, lead and zinc sulfides, for example iron sulfide and magnetite It has been described for use in sectors where it is desirable to selectively collect or select from other gangue sulfides and other gangue materials such as silicates, carbonates, and the like. In certain cases, however, it may also be used when it is necessary to collect all the sulfides in the ore including copper sulfide minerals (ZnS) and iron sulfides, ie iron sulfide and magnetite.

More specifically, there are bulk sulfide ores or complex sulfide ores containing a large amount of iron sulfide minerals such as iron sulfide and free iron ore. In such complex sulfide ores, flotation of iron sulfide minerals is often required to obtain useful sulfur from these minerals and the process can be continued later to produce sulfur and sulfur reagents. Under these circumstances, a bulk sulfide flotation method is required, i.e., a flotation flotation method in which all sulfide minerals are suspended and collected. Bulk sulfide flotation is also required for beneficiation of precious metals from noble metal-containing iron sulfides and pyrrhotite minerals.

However, sometimes these bulky sulfide or complex sulfide ores contain not only useful metals such as copper, zinc, lead, nickel, cobalt, etc. as sulfides, but also closely related to silica and siliceous materials as well as Contains gangue materials such as carbonates.

Such bulky sulfide ores or complex sulfides are not uncommon and eliminate a series of distinctive problems in foam flotation. The bulk sulphide flotation method for such ores cannot be successfully performed under conventional flotation conditions, for example, at a value of 10.0 pH, because the usefulness of iron sulfide and pyrrhotite is degraded at high pH values. At a pH value of 3.0-5.0, bulk sulfide flotation uses many conventional catchers, such as xanthate, but sulfuric acid as a regulator to reduce the pH of the flounder to the pH value. Since the carbonate gangue minerals present in these composite ores are acid soluble, the result is that, for example, a large amount of sulfuric acid of about 10-12 pounds / ton (ore) is required, which is not economical, and calcite, dolomite, etc. The use of sulfuric acid with ores containing alkaline earth metal carbonates, such as, eventually leads to the formation of large amounts of insoluble alkaline earth metal sulfates, which eventually form very serious scale on the plant, making frequent and costly shutdowns inevitable again. . At light teeth pHs in the range of about 6.0-9.0, bulk sulfide flotation using conventional catchers such as xanthate is not optimal.

Unexpectedly, it has been found that the novel and improved hydrocarboxycarbonyl thionomarbamate catcher of the present invention is optimal for bulk sulfide flotation from sulfides containing ores under certain conditions. In accordance with this aspect of the invention, the foamed flotation is carried out at neutral or weak alkali pH values, more specifically at pH 6.0-9.0 (including 9.0) and the hydrocarboxycarbonyl thionocarbamate catcher of the invention Using a large amount, i.e. about 0.1 to about 1.0 pounds per tonne, otherwise indicated, about 0.3 moles / metric tonnes (ore) or higher results in optimal bulk sulfide flotation.

After preparing the bulk sulfide concentrates by flotation using the pH conditions and a specific amount of catcher, useful sulfides of copper, lead, and zinc are converted to higher pH values, i. By separating the large amount of iron sulfide present in the bulk concentrate, useful sulfides can be collected and iron sulfides can be selectively suppressed.

In the past, xantate catchers were used in bulk flotation with pH values of 3.0-5.0, and the second stage flotation, which selectively suppressed iron sulfide, only operated at a pH value of about 11.0. This is because iron sulfide rejection of the catcher is poor at a pH value of 11.0 or lower. As can be seen, a significant amount of lime had to be added to adjust the pH for the second stage flotation. Now, according to this aspect of the present invention, the use of the hydrocarboxycarbonyl thionocarbamate catcher allows bulk sulfide flotation at higher pH values 6.0-9.0, the second stage flotation The amount of lime consumption required to separate useful metal sulfides from iron sulfide is reduced. Moreover, the hydrocarboxycarbonyl thionocarbamate catcher of the present invention is a much stronger catcher for copper, lead and zinc in the pH range of 9.0-11.0, whereby the second stage flotation is sufficient to inhibit iron sulfide. It can be carried out at a pH value, in which case it is not necessary to raise the pH above 11.0 and therefore the lime consumption is further reduced.

Other objects and advantages of the novel and improved catchers and methods of the present invention will be apparent from the following examples, which are only intended to enable those skilled in the art to better understand and practice the present invention. Is illustrated.

[Manufacture 1]

[Synthesis of ethoxycarbonyl isothiocyanate]

A reflux condenser, protected from moisture by a drying tube containing anhydrous calcium sulfate, is mounted in a heating mantle with three branched round bottom flasks, an addition funnel and a mechanical stirrer of fixed stage 2 l. Into the flask was placed 700 ml of dry acetonitrile and 194 grams of potassium thiocyanate. The mixture is heated to 70 ° C. with stirring and external heating is stopped. After 40 minutes, 217 grams of ethylchloroformate from the addition funnel are added with stirring. The exothermic reaction begins. When the mixture becomes thick, it turns yellow. After the addition is complete, the temperature of the reaction mixture reaches 77 ° C. The reaction mixture is stirred for 3 hours without external heating. The reaction mixture is then cooled to room temperature and the precipitate is removed by filtration. The precipitate cake is washed with anhydrous acetonitrile. The filtrate and washings are combined and concentrated by evaporation under reduced pressure. The residual liquid is distilled through a fractional distillation tube. 86.9 grams of ethoxycarbonyl isothiocyanate, a colorless liquid boiling at 45 ° C./11 mm Hg or 48 ° C./12 mm Hg, are calculated.

[Manufacture 2]

[Synthesis of N-ethoxycarbonyl-O-isopropyl thionocarbamate]

40 ml of isopropyl alcohol is added to 10 grams of ethoxycarbonyl isothiocyanate (preparation 1) and the reaction solution is mixed well by stirring. After the exotherm was completed, the reaction solution was left overnight and the progress of the reaction was monitored by infrared spectroscopy of the reaction solution. The completion of the reaction can be seen by the disappearance of the absorption band at 1960-1990 cm ⁻¹ for the N = C = S group. Excess isopropyl alcohol is removed by stripping under reduced pressure to obtain an oily residue. Crystallization from petroleum ether (bp 35-60 ° C.) yields 13.1 grams of colorless crystals, N-ethoxycarbonyl-O-isopropyl thiocarbamate, melting at 32-33 ° C.

[Manufacture 3]

[Synthesis of N-ethoxycarbonyl-O-isobutyl thionocarbamate]

40 ml of isobutyl alcohol is added to 10 grams of ethoxycarbonyl isothiocyanate of Preparation 1. After the reaction is completed, excess isobutyl alcohol is removed by stripping under reduced pressure. 15 grams of N-ethoxycarbonyl-O-sobutyl thionocarbamate, a colorless oil, was calculated.

[Manufacture 4]

[Synthesis Reaction Sequence of N-phenoxycarbonyl-O-ethyl Thiocarbamate]

시간동안 교반시킨다. (GC는 페닐 클로로포르메이트가 완전히 반응되었음을 나타냈다). 10㎖의 무수에틸알코올을 첨가한다. 반응혼합물을 교반시킨 후, 반응의 진행을 페녹시카르보닐 이소티오시아네이트가 완전히 소모됐을때까지 IR에 의해 모니터한다. 50㎖의 물을 첨가하여 고체물을 용해시킨다. 반응혼합물을 250㎖ 분리깔대기로 옮긴다. 유기질층을 모으고, MgSO₄로 건조 및 여과시킨다. 여액을 휘발성 물질의 스트리핑하에 의해 농축시킨다. 20.4그램무게의 고체를 얻는다. 그 고체를 헥산으로부터 재결정한다. 순수생성물은 81-83℃에서 녹는다.A reflux condenser, thermometer, addition funnel and mechanical stirrer are mounted in three 250 mL round bottom flasks. To the reaction flask is added 100 ml of ethyl acetate and 9.7 grams of potassium thiocyanate. The mixture is stirred and heated. 15.7 grams of phenylchloroformate is added to the mixture over 30 minutes from the addition funnel. After the exotherm is complete, the reaction mixture is

Stir for time. (GC indicated that phenyl chloroformate was fully reacted). 10 ml of anhydrous ethyl alcohol is added. After stirring the reaction mixture, the progress of the reaction is monitored by IR until the phenoxycarbonyl isothiocyanate is completely consumed. 50 ml of water is added to dissolve the solids. The reaction mixture is transferred to a 250 ml separatory funnel. The organic layers are combined, dried over MgSO ₄ and filtered. The filtrate is concentrated by stripping of volatiles. Obtain a solid weighing 20.4 grams. The solid is recrystallized from hexane. Pure product melts at 81-83 ° C.

The hydrocarboxycarbonyl thionocarbamates synthesized above are used as catchers for various sulfide ores and tested for phototreatment at various pH values to compare with conventional sulfide catcher compounds. Other homologues and / or homologues of the hydrocarboxycarbonyl thionocarbamates used in the examples below can be prepared according to substantially the same preparation method as desired by substituting appropriately active hydroxyl compounds. Compounds having R ² groups can be obtained. In each of the following examples, the following general preparation and testing procedures were used:

Crush sulfide to -10 mesh size. Approximately 500-2000 grams of compound were loaded into a steel ball mill at 5.3-10.7 kg with a strong ball load and 50-75% solids for about 6-14 minutes or generally about 10-20% +65 mesh, 14-30% + 100 Wet grinding until a dendrite with size distribution represented by mash and 40-80% -200 mesh is obtained. Lime and sulfuric acid are adjusted to the required pH using a pH adjuster. Generally, such regulators are added to the polishing machine. The foam used was added to the grinder in some experiments and to flotation in other tests. In some particular tests, 50% catcher is added to the grinder, otherwise the catcher is added in the first and second control steps of the flotation cell.

The reduced sized brine is transferred to a Denver D12 rectangular flotation cell with or without foaming and catching agent additives. The volume of the brine is adjusted to 1200-2650 ml by addition of water to give a densities of about 20-45% solids and a densities in the cell about 2 cm below the lip.

A catcher and / or foaming agent is added to the brine with stirring at about 1100-1400 rpm. The tailings are adjusted for 2 minutes, at which time pH and temperature are measured. At the control end of 2 minutes, air is supplied at about 5-7 liters / minute from the compressed air cylinder. The foam flotation is continued for about three minutes while collecting the first phase concentrate. Thereafter, the air supply is stopped, more catcher and foaming agent is added, and the tailings are further controlled for 2 minutes. After the second two minute adjustment step, the air is supplied and the second phase concentrate is collected. As soon as the flotation has been completed, the flotation frequency is determined in advance so that no foam is generated. The concentrates and tailings of the first and second stages were filtered, dried, sampled and assayed for copper, iron and sulfur. Tap water at the required temperature was used in all tests. The abbreviation t is used to represent standard tones, eg 2000 pounds. And T represents a metric ton, for example 1000 kg or 2204 pounds.

Example 1

[Natural pH flotation]

Southwestern US copper ore with 0.3% copper head assay and 1.7% iron sulfide (FeS ₂ ) headsalt was used in this series of tests. In this embodiment and the following examples, gangue iron minerals such as iron sulfide, pyrrhotite, and the like are referred to simply as iron sulfide for the purpose of convenience. The main copper minerals were whistle and chalcopyrite.

460 grams of ore are ground to 60% solids for 8.5 minutes to obtain a photonic slurry having a size distribution of 17.5% + 65 mesh, 35.2% + 100 mesh and 41% -200 mesh. The natural pH of the flounder was ie 5.5 without the addition of lime or sulfuric acid pH regulators externally. The tailings are adjusted to 30% solids with a foaming agent and designated catcher consisting of 50 / 50w / w / MIBC / pine oil added at 0.08 pounds / tonne (ore) and subjected to primary and secondary flotation according to the procedure described above. . The results of the catcher and the concentrate and tailings used were shown in Table 1 below:

TABLE 1

Natural pH 5.5; Foaming agent-1: 1 MIBC / pine oil 0.081bs / t

Head Deposit: Cu-0.3% FeS ₂ -1.7%]

A, : 미네렉 코포레이션, 미합중국, 매릴랜드 발티모아. ^a) MINEREC

A,: Minerek Corporation, United States, Maryland, Baltimore.

The conventional catcher shown in Examples A-G is much weaker than Example 1 of the present invention at this pH.

The hydrocarboxycarbonyl thionocarbamates of Example 1 not only provide the maximum copper recovery for the tested catcher, but also the maximum copper grade at the iron sulfide rejection tolerance.

Example 2-3

In the examples below, copper-molybdenum ores in the southwestern United States were used, with head58 0.458% copper and 2.2% iron sulfide. Ore is the main copper mineral, containing ore, brass ore. The ore is steel ball milled as 63% solids to produce dendrite of about 16.4% + 65 mesh, 30% + 100 mesh and 43.8% -200 mesh sizes. The natural pH in the brine of polished ore is 5.0. The foaming agent used was 1: 1 MIBC / pine oil added at 50 grams / metric ton (T). For a more precise and meaningful comparison, the catcher was used as equimolar, ie 0.03 mol / T is about 0.01 pounds / ton. In addition, screening / performance dimensions were calculated for each catcher tested.

More specifically, the screening / performance index is defined and calculated by the following equation:

The selection index for copper is a convenient way to measure not only the copper recovery of the catcher but also its selectivity to reject iron sulfide. For example, with this particular ore, if 90% recovery of copper and 50% peak of iron sulfide are optimal, then the optimal sorting index for copper is:

Will be.

The catchers tested and the results obtained are shown in Table 2 below.

TABLE 2

Natural pH 5.0 (no lime);

Foaming agent-1: 1 MIBC / pine oil (50 g / T);

Catcher (0.03 Mole / Ton (approximately 0.01 Lb./t))

* This showed an excellent high copper recovery.

All other data represent reproducible results.

The results in Table 2 clearly show that the catcher of the present invention is superior to the conventional catcher of Example HP. Example 2-3 shows high copper recovery with satisfactory iron sulphide rejection. Only the catcher of Example 2-3 gave I _cu close to the optimum 0.5.

Example 4-7

In the following examples, various catchers were tested using the same ore as in Examples 2-3 to show that the superiority of the catchers of the present invention is manifested even at higher levels of use and limited to only one use. Was measured. The tested catchers, the amounts used and the results obtained are shown in Table 3 below:

TABLE 3

준위에서도 종래의 포수제보다 성능이 우수함을 보여준다.As shown in the data of Table 3, the new and improved catchers of Examples 4 and 5 showed better copper recovery and I _cu values than the conventional catchers of Example Q at 0.04 mol / T usage, respectively. Moreover, the conventional catcher RW was inferior to Examples 4, 5, 6 and 7 even at an amount of 0.14 mole / T. These data indicate that the novel catchers of the invention at pH 5.0 have even significantly reduced usage levels, i.e. 1/5 in Example 6 and in Example 7.

It also shows that the performance is superior to the conventional catcher at the level.

Example 8-14

Using the same ore, the performance of the conventional catcher and the catcher of the present invention were compared in terms of the structural effects on the performance against known dialkyl xanthogen formates and the length of the chain of the hydrocarbon.

TABLE 4

Natural pH 5.0 (no lime);

Foaming agent-1: 1 MIBC / pine oil (50 g / T);

Catcher (0.03 Mole / Ton (approximately 0.01 Lb./t))

Except for the diethyl conjugation from the results of Table 4, for example, all the catchers of the present invention of Examples 8-14 are better than the corresponding conventional catchers substituted by the same R ¹ and R ² groups It can be seen that the number of times. I _cu values are also better. The amyl analog of Example 12 shows the best copper recovery and I _cu values.

Example 15-17

In the examples below, South American copper-molybdenum ores were used. This ore contains 1.65% copper, 2.5% iron sulfide and 0.025% molybdenum. Copper exists as copper ore minerals such as whiskers, chalcopyrites, bronzes, semi-hard ores, and malachite and red copper. Although the ore contains a large amount of brass, some ore is included.

Approximately 500 grams of -10 mesh ore are wet polished at 5.3 kg of steel ball load and 63% solids for 13 minutes in a steel ball mill to obtain optical teeth having a size distribution of 14% + 100 mesh and 52% -200 mesh. 10.5 g / T diesel oil is also added in all tests.

The natural pH of the flounder is 5.5. Standard catchers used for this ore include, for example, neutral alkyl xanthogen alkylformate, gasoline and 4-methyl-2-pentanol (MIBC), which is ethyl xanthogen ethylformate (MINETRAC A). Each in a ratio of 60:30:10. The foaming agent used is a polypropylene glycol monoalkyl ether such as polypropylene glycol monomethyl ether and is added in an amount of 60 g / T. According to the flotation test procedure described above, the standard catcher in mixed or unmixed form is compared with the catchers of the present invention in various usage ranks, and the catchers are added to the flotation cell in the first and second steps. do. The test results are reported in Table 5 below.

TABLE 5

[Natural pH 5.5 (no lime and H ₂ SO ₄ );

Foaming agent-60 g / T;]

As exemplified by the data in Table 5, the hydrocarboxycarbonyl thionocarbamate catchers of the present invention in unmixed form in Examples 15-17 are conventional neutral xanthogens used in pure or mixed form. Compared to promate catcher, it is better in terms of% copper recovery and grade.

Example 18-25

In the examples which follow, the catchers of the present invention in mixed or unmixed form are compared to neutral xanthogen formate catchers using the same test procedure on copper-molybdenum ores of the same Nami, but this time controlled and suspended Before the beneficiation test, 5.0 kg / T sulfuric acid is added to adjust the pH of the sludge slurry to 4.0. In addition, the surface water agents are added only to the flotation cell during the first and second adjustment steps. The catchers used and the results obtained are reported in Table 6 below:

TABLE 6

[Cu = 1.65%, FeS ₂ = 2.5%

PH 5.0 adjusted with 5.0 kg / T sulfuric acid

Foaming agent Dow 1012 = 60g / T]

Table 6 shows the standard of the mixed or pure form of the catchers of the present invention in the pure form shown in Examples 18-20 and 23-25 or the mixed form shown in Examples 21 and 22, at all levels of use tested. It has been shown to exhibit stronger catcher activity compared to xanthogen formate catcher. The copper recovery of Examples 18-25 is on average 3% higher with no loss in copper grade, but also shows an increased recovery at significantly lower usage than the corresponding standard catcher. The benefit of the use of the hydrocarboxycarbonyl thionocarbamate catcher of the present invention is the economic advantage, that is, better recovery and grade can be obtained at lower reagent cost.

It is noteworthy that for this particular ore, the recovery of the resulting iron sulfide is significantly higher, and almost equal to the recovery of copper. As a result of the microscopic analysis, iron sulfide in this particular ore in the polisher used was closely related and / or contained in the copper mineral, so high copper recovery for this ore inevitably resulted in high recovery of iron sulfide. High iron pyrite recovery was observed for all catchers tested in Table 6, but only the catchers of Examples 18-25 showed the highest I _cu values for this ore at pH 4.0. Furthermore, as shown in Example 22 of Table 6, the mixture containing only 36% of the hydrocarboxycarbonyl thionocarbamate catcher showed higher copper recovery than that obtained from the standard catcher.

Example 26-27

The following examples were performed to investigate the sensitivity of the inventive catcher to pH using the same South American ore as used in Examples 16-25 and to test the potency of the catcher under strong acid conditions. The reagents and flotation conditions used in Examples 18-25 were used in the following tests. The amount of catcher used is 5 g / T. Sulfuric acid was adjusted to the labeled pH value using sulfuric acid. Catchers were tested at 2.75 and 3.0 respectively and the results obtained are reported in Table 7 below:

The data in Table 7 clearly shows that the catcher of the present invention has significantly better performance than conventional neutral xanthogen formate catcher, even under strong acid conditions, and in general the hydrocarboxycarbonyl thionocarba of the present invention Mate catcher is not pH sensitive. The standard catcher showed only 20-25% copper recovery, while the novel catcher of the present invention shown in Examples 26 and 27 showed about 80% copper recovery. This result is probably due to the much higher hydrolytic stability of the catcher of the present invention compared to the standard catcher.

Example 28-30

Southwestern United States ore with the same 0.458% copper and 2.2% iron sulfide headsalt as used in Examples 2-14 was used in this flotation process and the foaming agent used was 1: 1 pine oil added at 50 g / T. / MIBC mixture. The pH was adjusted to the indicated acidic value using sulfuric acid, and sulfuric acid was added at about 1.7 kg / T for pH 4.0.

The selectivity and catcher strength of the new catchers over a number of standard catchers under acidic conditions were evaluated using the specific ores described above. The tested catchers and the calculated results are reported in Table 8 below:

TABLE 8

[pH 4.0, sulfuric acid 1.7 kg / T, foaming agent-1: 1 pine oil / MIBC 50 g / T, use amount of catcher; 0.01 Mole / T (about 2 g / T)]

The results in Table 8 clearly show that the novel catcher of the present invention (Examples 28-30) is superior to the conventional catcher (Example TT-DDD) in terms of copper recovery, copper grade, and selection index. In addition, it can be seen from Table 8 that high copper recovery (approximately 95%) is achieved in the water-soluble ion catcher dithio phosphate and xanthate by using 10 times or more of the amount required in the new catcher. Yes, but this is also lower than the number obtained with the new catcher (97%). The copper recovery obtained with ethyl xanthogen ethyl formate, a neutral catcher deemed suitable for the acidic range, was only 91-95% (Example ZZ-DDD). Moreover, the performance of this catcher is very sensitive to small variations in pH, with a slight decrease in pH from 4.0 to 3.9 or 3.7, copper recovery from 92.3% to 65.2% (compare Examples ZZ and AAA) and 91%. At 54% (Examples BBB and CCC). However, this was not the case with the novel catchers (Examples 28 and 29). This excellent stability with respect to pH is a significant advantage of the novel catcher over conventional catchers, which is particularly advantageous under practical operating conditions where pH fluctuations are inevitable.

Example 31-32

It is generally believed that neutral oil catchers are most effective when added to a polishing machine instead of flotation cells. This is generally true if the catcher is very water-insoluble and insoluble. However, it has been found that the hydrocarboxycarbonyl thionocarbamate catcher of the present invention is easily dispersible, although insoluble in all practical uses. Tests were conducted to evaluate whether the dispersibility of these catchers provided another benefit in use. Two flotations are carried out in this regard, one of which adds 50% of the catcher to the polishing machine and the other 50% of the second stage flotation into the flotation cell, and the other 50% of the catcher. Is added to the cell in the first stage flotation and the remaining 50% is added to the cell in the second stage flotation. In this example, the same ore and catcher as used in Examples 4-14 were used. Flotation was carried out and the concentrates and tailings were assayed for copper.

The results obtained are reported in Table 9:

TABLE 9

From the results in Table 9, it can be seen that unexpected improved results can be obtained by adding the catcher of the present invention to the flotation cell rather than to a polishing machine. Comparing Example 31 and Example 32, adding the catcher of the present invention only to the cell increases the total copper recovery, for example, while the copper recovery for Example 31 is 96.3%, Example 32 The copper recovery for is 97.5%. This difference is due to the adsorption of the catcher to iron useful in steel ball milling / polishing apparatus, although the novel catcher of the present invention has a screening force against iron, so that a slight amount of catcher's catcher to copper is subjected to It can be described as being lost.

Interestingly, the addition of the novel catcher of the present invention to the flotation cell instead of the polishing machine unexpectedly greatly improves the kinetics of the flotation. More specifically, the improved kinematics is explained by better copper recovery in the first stage flotation. As will be readily appreciated by those skilled in the art, in a typical flotation process, the ore is flocculated to provide rougher concentrates and tailings. In general, the tailings are discarded and the minerals are regrinded, reconditioned and then involved in a cleaner flotation. This yields selected concentrates and selected tailings. Generally, the concentrate is dried and transported for smelting or other refining. Select tailings are accompanied by scavenging flotation after reconditioning. The blue mineral can then be combined with the crystal of mineral. The fresh tailings can be combined with the main feed of shipbuilding flotation. In the reconditioning step between shipbuilding, refinery and blue flotation, the pH of the slurry is generally increased to obtain better selectivity and recovery.

As can be seen from the data in Table 9, when the novel catcher of the present invention is added to the cell, a much higher and faster catcher activity can be obtained than when 50% of the catcher is added to the polishing machine. If the catcher is only added to the cell (Example 32), it is significantly different from Example 31, with about 84% of copper suspended in the first stage flotation, while in Example 31 only 22.1% of copper Floating beneficiation in the first stage. Improved flotation kinetics yields a first stage diluent containing more copper, further indicating that reagent consumption can be reduced by appropriate reagent supply control, and the number of cells in the flotation bank It's a decrease. The total output of the plant can also be increased.

Example 33-34

The examples of flotation below are performed using southwestern copper-molybdenum ore with 0.45% copper and 2.2% iron sulfide headsalt at about pH 8.3. The foaming agent used is a 50/50 pine oil / MIBC mixture and is added at 50 g / T and the catcher is added at 0.01 mol / T (about 2 g / T). Lime is added in an amount of 1.76 kg / T to adjust the pH of the brine to about 8.3. The conventional flotation process using this ore provided an operating pH of 11.2-11.3 which required lime addition of about 4.412 kg / T. The catchers tested and the results obtained are described in Table 10 below:

TABLE 10

[pH 8.3, lime 1.76 kg / T

Foaming agent 1: 1 Pine oil / MIBC 50g / T

Catcher Consumption 0.01M / T (about 2g / T)]

From the results in Table 10, the superiority of the hydrocarboxycarbonyl thionocarbamate of the present invention with respect to ethyl xanthogen ethyl formate, which is a conventional catcher, can be seen. Examples 33 and 34 provided about 5% higher copper recovery than those obtained with conventional catchers of Examples EEE and FFF, and the copper grade and Icu values were also significantly higher. From these results, it can be seen that the lime consumption required for treating the ore was reduced by 60% for the present invention as a consumption of 1.76 kg / T as compared to 4.412 kg / T consumption for the conventional catcher.

Example 35-36

The same flotation test is carried out using the same amount of ore, foaming and catching agent as used in Examples 33-34, except that pH 7.2 is used. To obtain this pH, about 1.18 kg / T of lime is added, compared to the standard 4.412 kg / T of stone capacity required to provide pH 11.2-11.3 used in the prior art flotation of these ores. A 73% reduction in lime consumption is shown. The tested catchers and the results obtained are reported in Table 11 below.

TABLE 11

[pH 7.2, lime 1.18 kg / T,

Foaming agent 1: 1 Pine oil: MIBC 50g / T,

Catcher Consumption 0.1M / T (about 2g / T)]

As can be seen from the data in Table 11, even at pH 7.2, the novel and improved hydrocarboxycarbonyl thionocarbamate catcher of the present invention provides the best metallurgical performance compared to the conventional catcher of Example GGG-KKK. It has good copper recovery, good concentrate grade and high Icu value, which is 4-45% higher than that obtained with conventional catchers.

Example 37

The same flotation test is carried out using the same amount of ore, foaming agent, and catching agent as used in Examples 33-36, except that the pH value is 10.0. About 2.75 kg / T of lime is added, which represents a 38% reduction in lime consumption compared to the conventional 4.412 kg / T used in the prior art methods. The results tested at pH 10.0 are reported in Table 12 below:

TABLE 12

[pH 10.0, lime 2.75 kg / T,

Foaming agent-1: 1 pine oil / MIBC -50g / T,

Catcher Consumption 0.01 M / T (about 2g / T)]

The results in Table 12 show that, at pH 10.0, the hydrocarboxycarbonyl catcher of Example 37 provided about 1% lower copper recovery than the conventional catcher of Example, but with significantly better selectivity for iron sulfide recovery, ie 76 of Example LLL. Compared with%, Example 37 shows only 32% iron sulfide recovery, which means that the Icu value is high.

[Example 38-43]

The examples below use southwestern copper-molybdenum ores of headsalts of about 0.778% copper and about 5.7% iron sulfide. This ore is one of the most complex of all ores tested in terms of complex minerals, low total copper recovery, high lime consumption, and foaming problems. The ore mainly contains whistle ore, but the iron sulfide in the ore is excessively contained whistle or bronze. Therefore, the beneficiation of iron sulfide in shipbuilding flotation is not possible and has not been attempted.

880 grams of ore are adjusted with 550 mg / T ammonium sulfide and polished for 5 minutes with 55.5% solids to obtain densities with size distributions of 17.4% + 65 mesh, 33% + 100 mesh and 47.4% -200 mesh. The brine is then adjusted to 1500 rpm and 20.55 solids.

The standard operating pH of this ore is 11.4-11.5 and N-ethyl-O-isopropyl thionocarbamate was used as standard catcher. The lime consumption required to provide a working pH of 11.4-11.5 is about 3.07 g / T. The standard foam is cresyl acid and about 150 g / T is added.

The results of testing the catcher under the indicated conditions and in the amounts used are described in Table 13 below:

TABLE 13

[Headspin Cu = 0.778%, FeS ₂ = 5.7%

Foaming agent-cresyl acid-150 g / T,

Catcher usage and pH-see below]

From the results in Table 13, the novel catcher of the present invention (Examples 38-40 and 42-43) has excellent metallurgical performance at pH 8.0 and 9.0 compared to the standard catcher at pH 11.5 (Example NN-SSS). It can be clearly seen that. Significantly reduced lime consumption (7.5% reduction in total lime consumption to pH 8.0 and 25% reduction in total to pH 9.0) and reduced catcher by using new catchers at pH 8.0 or 9.0 Acceptable metallurgy can be achieved with an amount of use (0.105 M / T instead of 8.210 M / T required for standard catcher at pH 11.5).

Example 44-47

South American Cu-Mo ores containing 1.844% Cu and 4.25 iron sulfide were used in the following tests. Copper minerals are mainly whistle ore, brass ore, and bronze ore ore.

510 g of ore are wet pulverized in 68% solids for 7.5 minutes to obtain a brine with a size distribution of 24.7% + 65M, 38.3% + 100M and 44% -200M. In all tests, 2.5 g / T di-secondary butyl dithio phosphate is added to the polisher. Lime is also added to the polishing machine to obtain the pH required in flotation. The brine is transferred to a flotation cell and adjusted to 1100 rpm and 32% solids.

This ore is a novel catcher of the present invention and is used for further flotation testing in a weak alkaline circuit. The standard catcher consists of about 30-40 g / T sodium isopropyl isopropyl xanthate and 2.5 g / T di (secondary-butyl) dithiophosphate with a standard flotation pH of 10.5. At this pH, the lime consumption is about 0.5 g / T. The standard foaming agent is 1: 1: 1 polypropylene glycol monomethyl ether / MIBC / pine oil at 20-25 g / T. The catchers tested and the results obtained are described in Table 14 below:

TABLE 14

[Head Cu = 1.85%, FeS ₂ = 4.2%

Foaming agent-1: 1: 1 Dow 250 / MIBC / pine oil-25.5g / T

Catcher usage and pH-see below]

From the results in Table 14, it can be seen that the novel catcher of the present invention shows excellent performance in terms of reduced copper consumption and copper recovery (no reduction in copper grade) and iron sulfide rejection. The standard catcher was unacceptably low in copper recovery even at increased pH of the catcher.

Example 48

In the previous embodiment, the novel and improved hydrocarboxycarbonyl thionocarbamate catcher of the present invention is used in shipbuilding or first stage at reduced usage of catcher and with reduced lime consumption or without using lime. Compared to many conventional catchers for various ores in flotation, the performance was even better. In practice, the concentrate is selected in the first or more stages to obtain high grade copper minerals or copper-molybdenum mineral concentrates which are further processed to produce metals.

The following examples provide for the production of higher grade copper concentrates for smelting or similar use using novel and improved hydrocarboxycarbonyl thionocarbamate catchers in selected flotation systems. To illustrate.

In the examples below, the same ore as used in Examples 44-47 is used. The first step or shipbuilding flotation is carried out according to the method of Examples 1-47, and the concentrate is filtered and dried and then regrind to obtain about 40% solids. Adjust the pH of the regrind to lime and add more necessary catcher and foaming agent. After regrinding the polished tailings, it is resuspended with distillate as conventionally to obtain concentrate concentrates and concentrate tailings. Selected tailings are gradually selected at higher pH values, with or without the addition of a catcher and foaming agent, and finally a cooler at pH above 11.0 with addition of a catcher to flotation any residual copper minerals. Each step product is isolated and analyzed.

Table 15, below, shows the results obtained with ore in the shipbuilding flotation and the second step or in the flotation flotation, using a standard sodium isopropyl xanthate catcher at pH 11.0 as a control. In the two-stage flotation flotation, an additional catcher was added in Example 48, because the amount added in the shipbuilding flotation was not enough to be passed up to the flotation flotation. The standard catcher is transported and present in a sufficient amount for the second stage flotation so that no further catcher is added during the second stage adjustment:

The results obtained are reported in Table 15 below:

TABLE 15

[Selected Flotation

Cu headspinning = 1.85%, FeS ₂ = 4.2%

Foaming agent-1: 1: 1 Dow 250 / MIBC / pine oil]

From the results in Table 15, it can be clearly seen that the novel and improved hydrocarboxycarbonyl thionocarbamate catcher of the present invention has excellent performance in shipbuilding and selected flotation, compared to the standard catcher control. More specifically, the grade of concentrate copper concentrate was about 2.2% (41.9% vs. 39.4%) higher for Example 48 than for control, and for Example 48 the copper grade of shipbuilding concentrate was similar to that above for control. % Higher. The total catcher used to achieve this copper rating was 17 g / T (Example 48) versus 30 g / T (control). Example 48 shows that using the catcher of the present invention achieves good copper recovery while reducing the catcher cost by about 45%. Less lime, i.e. 0.0226 kg / T vs. 0.951 kg / T (control), is used in Example 48 or selected rich floating circuits to show better recovery and grade with the catcher of the present invention. This saves more than 75% of the cost of lime consumption. The concentrate of Example 48 was 18.6% vs. 22.2%, with iron almost 4% less than the standard catcher, indicating good iron sulfide selectivity of the catcher of the present invention for the control. It is also evident that the good selectivity of the catcher of the present invention is low iron sulfide recovery in shipbuilding flotation, the standard catcher is 90% and the catcher of the present invention is 63.7%. Furthermore, in Example 48, the copper recovery in shipbuilding flotation provided by the catcher of the present invention was higher than that obtained with the standard catcher, and the standard catcher usage in shipbuilding flotation was less than 1/2.

Example 49

Bulk Sulfide Flotation Beneficiation

The following flotation tests use the eastern / southern copper-zinc-iron sulfide-magnetic iron ore of the United States. The ore contains 0.5-7% copper, 0.9% zinc, pyrrhotite and iron sulfide 30-35% iron as the ore. The ore also contains a large amount of carbonate gangue minerals such as calcite, dolomite and the like, and gangue in normal silicate or siliceous form.

In all tests, ball mill discharges from operating facilities are used. The slag contains about 40% -200 mesh of ore particles. About 4 liters of brine are transformed into 1-10 pounds / ton of concentrated sulfuric acid and 25% solids at 1800 rpm for 30 seconds. Next, catcher and foaming agent are added and the brine is adjusted for 2 minutes. Floating beneficiation is carried out for 4 minutes at a natural air flow rate at 1800 rpm stirring rate. Next, the first step concentrate is received and the tailings are adjusted with an additional foaming agent for 30 seconds, and then the second step concentrate is received over 4 minutes. The first and second stage concentrates and tailings are filtered and dried to assay for copper, iron, sulfur and zinc.

The results are reported in Table 16 below. The conventional catcher was sodium ethyl xanthate and the foaming agent was polypropylene glycol (OP 515 from Oreprep Inc.).

TABLE 16

Bulk Compound Flotation Beneficiation

Head deposit: Cu = 0.66, Zn = 1.00, Fe = 33.3, S = 19.24 Foaming agent = 35 g / T]

From the results in Table 16 below, the hydrocarboxycarbonyl thionocarbamate catcher of the present invention in Example 49 is about 25% lower usage and about 62% lower sulfuric acid compared to the conventional catcher of Example GGGG-IIII It can be seen that the consumption provides essentially the same metallurgical performance in bulk sulfide flotation.

The foregoing examples illustrate the significant improvements and benefits achieved with the novel and improved hydrocarboxycarbonyl thionocarbamates of the present invention over many conventional catchers known to those skilled in the art.

[Manufacture 5]

[Synthesis of ethoxy carbonyl isothiocyanate]

A 2 l three round bottom flask equipped with a reflux condenser protected from moisture by a drying tube containing anhydrous calcium sulfate, an addition funnel and a mechanical stirrer are mounted in the heating mantle. Into the flask was placed 700 ml of anhydrous acetonitrile and 194 grams of potassium thiocyanate. After heating the mixture to 70 ° C with stirring, external heating does not continue. After 40 minutes 217 grams of ethylchloroformate from the addition funnel are added to the mixture with stirring. At this time, the exothermic reaction begins. Thickening the mixture turns yellow. After the addition is complete, the temperature of the reaction mixture reaches 77 ° C. The reaction mixture is stirred for 3 hours without external heating. The reaction mixture is then cooled to room temperature and the precipitate is removed by filtration. The precipitate cake is washed with anhydrous acetone nitrile. The filtrate and washings are combined and concentrated by evaporation under reduced pressure. The residue is distilled through a fractional distillation tube. 86.9 grams of ethoxycarbonyl isothiocyanate, a colorless liquid boiling at 45 ° C./11 mm Hg or 48 ° C./12 mm Hg, are calculated.

[Manufacture 6]

[Synthesis of N-ethoxycarbonyl-N'-isopropyl thiourea]

7.1 grams of isopropylamine solution in 40 ml anhydrous ethyl ether was added dropwise to the solution of 15.5 grams of ethoxycarbonyl isothiocyanate (preparation 1) in 10 ml anhydrous ethyl ether with stirring for 30 minutes. The reaction vessel is cooled in an ice-water bath. The reaction mixture is left at ambient temperature. After the reaction is complete, the solution is concentrated by stripping most of the solvent under reduced pressure. The crystals are taken up by filtration and washing with hexane. The first crop weighed 8.1 grams, m.p. 52.5-54 ° C., secondary crop weight 7 grams, m.p. It was 52.5-54 ° C.

[Manufacture 7]

[Synthesis of N-ethoxycarbonyl-N'-isopropyl thiourea]

5.3 grams of ethoxycarbonyl isothiocyanate solution in 100 ml petroleum ether (b.p. 35-60 ° C.) was cooled with stirring in a cold water bath. To the solution is added dropwise 3.9 grams of isobutylamine in 50 ml of petroleum ether for 20 minutes. During the addition, the reaction flask is cooled in a cold water bath. After the addition is complete, the reaction flask is removed from the cold water bath and left at ambient temperature overnight. The solution is concentrated by stripping of most solvents.

The concentrated solution is cooled in a cold water bath. The crystals are taken up by filtration and washing with hexane. The product weighs 7.5 grams and melts at 50-52 ° C.

[Manufacture 8]

[Synthesis of Liquid Product Containing N-Ethoxycarbonyl-N'-Isopropyl Thiourea N-Ethoxy Carbonyl-N'-Isobufil Thiourea]

Into a 250 ml round bottom flask is added 11.86 grams of n-octane and ethoxycarbonyl isothiocyanate (Preparation 1). The flask is immersed in a cold water bath and the mixture is stirred for 5 minutes using a magnetic stir bar. To this solution is added dropwise 3.25 grams of isobutylamine and 2.63 grams of isopropylamine solution in 3.57 grams of n-octane from an addition funnel. The reaction flask is immersed in a cold water bath and then the reaction mixture is stirred during the addition of the amine solution. Next, the reaction flask was removed from the cold water bath and the reaction mixture was stirred at ambient temperature until the reaction was completed. The reaction solution is then concentrated by stripping of volatiles containing mainly-octane to yield 18.34 grams of liquid product. The product contains N-ethoxycarbonyl-N'-isopropyl thiourea and N-ethoxycarbonyl-N'-isobutylthiourea in a molar ratio of 1: 1, whereby the solid components of the two thioureas Is 87.4%.

The synthesized hydrocarboxycarbonyl thiourea is tested for beneficiation treatment properties at various pH values using as catcher for various sulfide ores and compared with the sulfide catcher compounds of the prior art. Other analogs and / or homologues of hydrocarboxycarbonyl thiourea can be used in the examples below, wherein the analogs or homologue compounds have corresponding suitable activities for preparing compounds having the desired R ¹ and R ² groups. It can be prepared according to substantially the same method as above using an amine compound instead.

In each of the following examples, the following general preparation and testing procedures are used.

Grind sulfide ore to -10 mesh size. Approximately 500-2000 grams of crushed ore was removed for about 8 minutes at 10.7 kg of steel ball load and 63% solids, or for about 10-20% +65 mesh, 14-30% + 100 mesh, 40-80%- Wet grind in a steel ball mill until a size distribution of 200 mesh is achieved. Lime and sulfuric acid are used as pH adjusters to adjust to the required pH. The foam used is added to the grinder in some tests and to the flotation cell in other tests. In some tests, 50% of the catcher is added to the polishing machine, or else the catcher is added to the first and second control steps of the flotation cell.

The downsized brine is transferred to a rectangular Denver D12 flotation cell with or without base and catcher additives. The volume of the tailings is adjusted to 2650 ml by the addition of water to the tailings density containing about 30-35% solids and to the tailings level in a cell of less than about 2 cm lip. Add catcher and / or foaming agent to the brine with stirring at about 1400 rpm. Adjust the brine for 2 minutes and measure the pH and temperature at this time. After 2 minutes of adjustment, air is supplied at about 7 l / min from the compressed air cylinder. The foam flotation is continued for about 3 minutes during which the first stage concentrate is received. Thereafter, the air supply is stopped, further foaming and catching agents are added, and the tailings are adjusted again for 2 minutes. After the second two minutes of the adjustment phase, the air is supplied again and the second phase concentrate is received. The number of flotations is determined in advance so that no foaming occurs as soon as flotation has been completed. Filtration, drying and sampling of the first and second stage concentrates and tailings are urgent for copper, iron and sulfur. In all tests, tap water at the required temperature is used. The abbreviation t is used to represent standard tones, ie 2000 lbs, with T indicating a meter, ie 1000 kg or 2204 lbs.

Example 50-51

[Acid Circuit Floating Beneficiation]

South American copper-molybdenum ore of 1.65% copper head spine and 2.5% iron sulfide head spine and 0.025% molybdenum are used in the examples below. The copper minerals present in the ore are some copper oxide minerals such as whiskers, chalcopyrites, bronzes, semicoal ores, malachite and red copper ores. Even if the ore contains a large amount of chalcopyrite, some ore is included.

Approximately 500 grams of -10 mesh powders of this ore were wet-polished for about 13 minutes at 63% solids in a steel ball mill containing 5.3 kg of steel ball load and distributed in size of 14% +100 mesh and 62% -200 mesh Calculates the brine having The sludge has a natural pH of 5.5, and sulfuric acid is used to adjust the brine pH to about 4.0. 10.5 g / T diesel oil is added to each example. In addition, the tested catcher is added to the flotation cell in the first and second adjustment steps. The flotation procedure described above was used in the individual flotation test.

The ore standard catcher is a mixture of 2.5 g / T sodium diethyldithiophosphate and 60/30/10 ratio ethyl xanthogen ethyl formate / diesel fuel / MIBC. For further comparison, the test is also carried out using other standard catcher, dialkyl thionocarbamate, as well as diethylxanthogen formate in pure form. The standard catcher and the novel and improved hydrocarboxycarbonyl thiourea catcher of the present invention are involved in one and two stage flotation. The percentage and grade of copper recovered and the percentage of iron sulfide recovery are determined by assuring the foam mineral and tailings of each flotation step. In addition, selection / performance indices are calculated for each catcher tested.

More specifically, the screening / performance index is defined and calculated by the following equation.

The selection index for copper is a convenient way to measure selectivity for rejecting gangue sulfides, such as iron sulfide and pyrrhotite, as well as the copper recovery of the catcher. For example, for 90% copper recovery and 92% iron sulfide recovery for this particular ore, the catcher's optimal sorting index for copper using this ore would be 0.08. The catchers tested and the flotation results obtained are described in Table 17 below:

TABLE 17

Acid Circuit Flotation Beneficiation

Head spin: Cu = 1.65%, FeS ₂ = 2.5%; pH = 4.0

Foaming agent = adjusted to pH 4.0 with 5.0 kg / T of polypropylene glycol monomethyl ether sulfuric acid of 60 g / T]

a. Ethyl xanthogen ethyl formate / diesel fuel / MIBC at 60/30/10 ratio.

The novel hydrocarboxycarbonyl thiourea catcher of the present invention shown in Examples 50 and 51 from the data in Table 17 is a conventional catcher mixture of Examples A'-D 'and sodium di of Example E'. It can be clearly seen that better metallurgical results are obtained with reduced usage compared to ethyldithiophosphate. Furthermore, the inventive catcher of Examples 50 and 51 performed better than the pure diethyl xanthogen formate catcher of Examples F 'and G' and the isopropyl ethyl thionocarbamate of Example H '. . Table 17 shows that higher copper recovery was achieved with reduced amounts of the hydrocarboxycarbonyl thiourea catcher of the present invention. In other words, it provided IC _cu values that only new catchers needed.

Example 52-55

[Weak alkaline pH flotation]

The southwestern ore of the United States containing 0.867% copper and 7.0% iron sulfide headsalt was used in the examples below, where the main copper mineral was brass ore and contained some whirling, eastern and rebounding light.

510 grams of ore are polished in a steel ball mill for 65 minutes to 8.5 minutes to obtain densities with size distributions of 5.8% + 65 mesh, 19% + 100 mesh and 53.3% -200 mesh. Lime is used to adjust the pH of the brine to the weakly alkaline value indicated. The foaming agent used is a 70/30 ratio polypropylene glycol / polypropylene glycol mono ethyl ether mixture added at 91 g / T. To make the comparison more meaningful, the use of equimolar ratio of catcher was used and reported in moles / metric tons. The standard catcher for this ore is sodium amyl xanthate, which is known to perform optimally at pH 11.5. The catchers were tested at various amounts and pH, and the results are shown in Table 18 below:

TABLE 18

Weak alkaline circuit flotation

Head Cu = 0.867%, FeS ₂ = 7.0%, foaming agent 91g / T, catchment agent usage and pH see below]

From the results in Table 14 the hydrocarboxycarbonylthiourea catcher of the present invention is equivalent to the standard sodium amyl xanthate catcher of Example I'-M 'with a lime consumption of only 10-30% at pH 9.0 or 10.0. It can be seen that the metallurgical performance was exhibited. It can be seen that this data showed high copper recovery and selectivity for iron sulfide at reduced lime consumption with the catcher of the present invention shown in Examples 52-55. It should be noted that the standard surface water agent exhibits very poor metallurgical performance at pH 9 and 10 as can be seen by the results of Examples I ', J' and L '.

Example 56-57

[Weak alkaline pH flotation]

South American copper-molybdenum ore containing 1.844% copper and 4.2% iron sulfide ore as headsalt is used in the examples below. The copper minerals present are mainly whistle ore, brass ore, or bronze and ore.

510 grams of ore are wet-polished with 68% solids for 7.5 minutes in a steel ball mill to obtain a debris with a size distribution of 24.7% + 65 mesh, 38.3% + 100 mesh and 44% -200 mesh. In all tests, 2.5 g / T di-tert-butyldithio phosphate is added to the polisher. Lime is also added to the grinder to obtain the required pH from flotation. The brine is transferred to a flotation cell to adjust to 1100 rpm and 32% solids. The foaming agent used was a 1/1/1 ratio polypropylene glycol monomethylether / MIBC / pine oil mixture added at about 0.04 b./T. The catcher of the present invention has been tested against a number of standard catchers and the results obtained are described in Table 19 below:

TABLE 19

Weak alkaline circuit flotation

Head Cu = 1.844%, FeS ₂ = 4.2%, Foaming Agent 20g / T, pH 9.0, Consumption Agent Consumption = 0.125mol / T.]

The data in Table 19 shows that the copper recovery at pH 9.0 provided with the novel hydrocarboxycarbonyl thiourea of the present invention shown in Examples 56-57 is essentially the sodium isopropyl shown in Example N'-O 'at pH 10.5. It is shown to be equivalent to the recovery of copper obtained with the xanthate standard catcher. In fact the standard catcher shows poor copper recovery at pH 9.0, even at the usage level of 0.19 moles / T as shown in Example P '. Using the novel hydrocarboxycarbonyl thioureas shown in Examples 56 and 57 compared to the standard control of Example N'-P ', it can be seen that the lime consumption is reduced by at least 50%. The catchers of Examples 56-57 give a satisfactory copper grade in the concentrate and show better selectivity for iron sulfide. On the other hand, other conventional catchers shown in Examples Q 'and R' show very poor copper recovery at pH 9.0.

[Weak alkaline pH flotation]

In the examples below, copper-molybdenum ore in southwestern United States with head spine of about 0.778% copper and about 5.7% iron sulfide is used. The ore is one of the most complex of all ores tested in terms of complex minerals, low total copper recovery, high lime consumption, and foaming problems. Ore mainly contains whirling ore, but iron ore sulfide in the ore excessively contains whirling or bronze. Therefore, beneficiation of shipbuilding flotation or iron sulfide in the first stage is not possible and is not attempted. 880 grams of ore were adjusted with 500 g / T ammonium sulfide and polished for 5 minutes in a steel ball mill with 55.5% solids to obtain a flounder having a size distribution of 17.4% + 65 mesh, 33% + 100 mesh 47.4% -200 mesh. The flounder is controlled at 1500 rpm at 20.4% solids.

The standard operating pH for the ore is 11.4-11.5, using N-ethyl-O-isopropyl thionocarbamate as standard catcher. The amount of lime consumed to provide an operating pH of 11.4-11.5 is about 3.07 kg / T. The standard foam used was about 150 g / T of cresylic acid.

The catcher was tested under the indicated pH conditions and the amount used, and the results are described in Table 20 below.

TABLE 20

Weak alkaline circuit flotation

Head Cu = 0.778%, FeS ₂ = 5.7%, foaming agent 150 g / T]

The data in Table 20 are essentially the same as those of the inventive hydrocarboxycarbonyl thioureas shown in Examples 58-63 at pH 8.0 or 9.0 with the standard catchers of Examples U ', V' and W 'at pH 10.3 or 11.4. This gives an equivalent copper recovery. Copper grades were also comparable. An important result is that the use of the novel catcher of the present invention can reduce lime consumption by at least 50% -75% of the standard lime consumption. In fact, for the catcher of the present invention shown in Examples 61-63, the lime consumption at pH 8.0 and the amount of 0.210 moles / T can be reduced to 92%, and at pH 9.0 and only 0.105 moles / T, 78 Can be reduced to%. At pH 9.0, the selectivity to iron sulfide is also acceptable and higher recovery of iron sulfide is unavoidable as described in the preceding paragraph for this ore. It should be noted that very poor copper recovery was obtained with many of the other conventional catchers shown in Example X'-CC '. It should also be noted that the standard catcher of Examples S'-W 'also results in very poor metallurgy at pH 8.0 and 9.0.

The foregoing examples illustrate that the novel and improved hydrocarbonylcarboxy thiourea catcher of the present invention exhibits significant improvements and advantages over many conventional catchers known in the art.

Although the method has been described with respect to any preferred embodiment, modifications or variations are possible within the scope of those skilled in the art. For example, instead of N-ethoxycarbonyl-O-alkylthionocarbamate and N-phenoxycarbonyl-O-alkyl thionocarbamate, other hydrocarboxycarbonyl thionocarba of the above formula Mates can be used as sulfide catchers in the present invention, examples of which include N-cyclohexoxycarbonyl-O-alkylthionocarbamate, N- (3-butene) 1-oxycarbonyl-O-alkylti Onocarbamate, N-alkoxycarbonyl-O-arylthionocarbamate, N-aryloxycarbonyl-O-arylthionocarbamate, and the like. Also, instead of N-ethoxycarbonyl-N'-alkylthiourea and N-phenoxycarbonyl-N'-alkylthiourea, other hydrocarboxycarbonyl thiourea of the above formula can be used as sulfide catcher in the present invention. For example, N-cyclohexoxycarbonyl-N'-alkylthiourea, N- (3-butene) -1-oxy carbonyl-N'-alkylthiourea, N-alkoxycarbonyl-N '-Arylthioureas and N-aryloxycarbonyl-N'-arylthioureas and the like. Moreover, as mentioned above, the process is not only a mixture of two or more hydrocarboxycarbonyl thionocarbamates as catcher component but also another known catcher which can be selected, for example, from (a)-(g) below. It may also be carried out using mixtures of at least one hydrocarboxycarbonyl thionocarbamate catcher in combination with the agent.

(a) xanthate or xanthate esters, for example each

(b) dithiophosphate

(c) thionocarbamate, for example

(d) dithiophosphinates, for example

(e) dithiocarbamates and derivatives thereof, eg, each

(f) trithiocarbonate and its derivatives, eg each

(g) mercaptans, for example

Wherein in each of (a)-(e) R ⁸ is C ₁ -C ₆ alkyl, R ⁹ is C ₁ -C ₆ alkyl, aryl or benzyl, R ¹¹ is hydroxy or R ⁸ , In (f), R ¹⁰ is C ₁ -C ₁₂ alkyl.

Instead of useful copper minerals, the process of the present invention is for example sulfide ores including lead, zinc, nickel, cobalt, molybdenum, iron, as well as precious metals such as gold, silver, platinum, palladium, rhodium, iridium, ruthenium and osmium and the like. It can be used for beneficiation of useful metals and other sulfide minerals from. All such changes and changes can be made by those skilled in the art, within the spirit and scope of the invention as defined in the appended claims.

Claims (6)

At least one compound selected from compounds of the formula

Wherein Z is OR ² or NHR, R ¹ is alkyl or phenyl, R ² is n-butyl, isobutyl, secondary butyl, n-amyl, isoamyl, phenyl, ethyl or isopropyl, and R is alkyl Provided that when Z is OR ² , R ¹ is ethyl or phenyl. The compound of claim 1, wherein R ¹ is ethyl and R ² is isopropyl. The compound of claim 1, wherein R ¹ is ethyl and R ² is isobutyl. (a) preparing an aqueous pulp slurry of finely divided, liberation-sized ore particles having a pH of 10.0 or less; (b) the slurry is adjusted to about 0.005 to 0.5 pounds of metal catcher consisting of about 0.01 to 0.2 pounds of foaming agent per tonne of ore and at least one compound having the following formula per tonne of ore,

(Wherein Z is OR or NR ² R ² , R and R ¹ are each alkyl and R ₂ is hydrogen or an alkyl group, at least one R ₂ is alkyl) (c) thereafter, according to the foam flotation procedure A method for beneficiation of non-metal sulfide minerals from non-metal sulfide ores by screening rejection of gangue sulfide minerals at a pH value of 10.0 or less, comprising foaming sulfide minerals. The method of claim 4, wherein in the metal catcher R ¹ is ethyl and R ² is isopropyl. The method of claim 4, wherein in the metal catcher R ¹ is ethyl and R ² is isobutyl.