AU2013218789B2

AU2013218789B2 - Thionocarbamates and processes

Info

Publication number: AU2013218789B2
Application number: AU2013218789A
Authority: AU
Inventors: Alexander Bradstock Tall
Original assignee: TEEBEE HOLDINGS Pty Ltd
Current assignee: TEEBEE HOLDINGS Pty Ltd
Priority date: 2012-02-06
Filing date: 2013-02-06
Publication date: 2017-09-28
Anticipated expiration: 2033-02-06
Also published as: PE20142323A1; WO2013116898A1; AU2017276237A1; PH12014501761A1; AU2013218789A1; CA2863802A1; CL2014002083A1

Abstract

Novel thionocarbamate compounds having one or more substituents with five or more carbon atoms have been produced and evaluated as collectors used in froth flotation processes for the recovery of minerals. The amounts of minerals being recovered are greater as compared to the results obtained from using a conventional collector as a standard when using the novel thionocarbamates. Not only is the amount of materials recovered increased, i.e. enhanced yield, but also the novel thionocarbamate collectors have enhanced selectivity by rejecting iron to a greater extent than the standard so that the purity of the mineral being recovered is increased. A method of making the novel thionocarbamates is described using novel xanthates and amines, including novel amines. The advantage of the processes and methods is that the xanthates used to produce the novel thionocarbamates do not need to be pre-treated by being dried, purified, isolated, but rather the xanthates can be used in the form as produced.

Description

THIONOCARBAMATES AND PROCESSES FIELD OF THE INVENTION

The present invention relates to processes and methods of making thionocarbamates and to thionocarbamates made by such methods and processes.

In one form, the present invention relates to methods and processes of making thionocarbamates from xanthates and to thionocarbamates made by such methods and processes.

In one form, the present invention relates to new xanthate compounds, particularly new xanthate compounds that are used to react with amines to form new thionocarbamates.

In one form, the present invention relates to new and/or different amines, particularly new and/or different amines used in processes of making thionocarbamates, including new thionocarbamates.

In one form, the present invention relates to collectors for use in froth flotation processes to recover materials of economic value in which the collectors are, or comprise, thionocarbamates made by the methods and processes of the invention either alone or in combination with other collectors, activators, frothers and the like, including combinations of different thionocarbamates or combinations of thionocarbamates with other types of collectors.

In one form, the present invention relates to methods and processes of recovering materials of economic value in froth flotation processes using thionocarbamates as collectors in which the thionocarbamates are made generally in accordance with the methods and processes as described herein.

The present invention finds particular application in making new thionocarbamates from corresponding xanthates for use as collectors in froth flotation processes for recovering valuable materials from naturally occurring materials such as ores and the like, including gold, silver, platinum, copper, nickel, lead, palladium, zinc, molybdenum, and other valuable minerals or similar, optionally while rejecting simultaneous iron recovery.

BACKGROUND OF THE INVENTION

Thionocarbamates are a class of compounds that have been used previously in the minerals and mining industries as reagents for the extraction of valuable materials, such as minerals, from naturally occurring materials, such as ores or the like, from waste products, such as smelter slags, tailings or the like, containing deposits of minerals or metals which are to be extracted from the waste products. Thionocarbamates are also known as thiourethanes and can be represented by the general formula RO-C(S)-NHR’ (General Formula I) in which both R and R’ are generally hydrocarbon radicals.

Although certain thionocarbamates have been available in the past, the range of commercially available thionocarbamates has been severely restricted to a small number of selected thionocarbamates, such as for example thionocarbamates of general Formula 1 in which the substituents represented by R and R’ are limited to the lower alkyl radicals containing from 1 to 4 carbon atoms, such as for example, methyl, ethyl, isopropyl and isobutyl. Whilst the use of such thionocarbamates having lower alkyl radical substituents, i.e. up to 4 carbon atoms, has met with some commercial success, there has been little, if any, investigations into the use of thionocarbamates having higher alkyl radical substituents or non alkyl substituents for use as collectors in ore froth flotation processes for the recovery of minerals. One of the reasons for the very limited investigations into thionocarbamates having higher alkyl substituents, or substituents other than alkyl substituents, is the problems encountered in actually preparing such thionocarbamates, such as for example, from corresponding xanthates because the xanthates were generally not in a usable form. In situations where xanthates are used as the precursors for the thionocarbamates, about the longest carbon chain of the substituents of the xanthate compounds that are currently available commercially is about 4 or 5 carbon atoms, such as for example, amyl xanthate, which is believed to be about the longest chain xanthate in commercial production currently. However, even amyl xanthate has met with only limited success commercially and is not generally used as a collector.

Xanthates having substituents of more than 4 carbon atoms are generally regarded as being unsuitable for use in commercial production of thionocarbamates since it is believed by many that one of the reasons is that such xanthates are not capable of being dried sufficiently or economically into a form which is suitable for use in the subsequent manufacture of the thionocarbamates in commercial production processes. Another reason for the reluctance to use xanthates having substituents of more than about 4 carbon atoms is that the xanthates, after having been made by current commercial manufacturing routes, remain as an untreatable or unusable mass which mass may contain many individual compounds, in addition to the xanthates of interest. This mixture of different compounds makes it extremely difficult to isolate the xanthates of interest. Additionally, the mass is difficult to handle for use in subsequent chemical reactions for forming the corresponding thionocarbamate.

Additionally, the mass containing the xanthate is often of either low purity or is unstable or both, making it either difficult or expensive, or both, to purify the xanthate in the mass to an acceptable level for use commercially, because of the physical state and/or chemical composition of the mass. Thus, for those reasons, there has been no incentive to use higher alkyl substituted xanthates in the past.

Surprisingly, it has now been discovered as a result of investigations by the inventor, that some xanthates having a wider variety of substituents represented by R and R’ can be made and/or can be used to react with at least some amines and/or for use in the manufacture of thionocarbamates to be used as collectors in froth flotation processes when made from the corresponding xanthates having substituents containing more than 4 carbon atoms.

In order to be able to investigate the characteristics of the new thionocarbamates and their suitability for use as collectors, first it was necessary to not only investigate the different xanthates potentially useful for forming the thionocarbamates, but it was also necessary to investigate the manufacture of the new xanthates by developing improved synthetic routes for making firstly the new xanthates themselves, and secondly making the new thionocarbamates from the new xanthates. The inventor has now been able to address both of these issues.

Additionally, the inventor has been able to make new and/or improved xanthates as well as the corresponding thionocarbamates by surprisingly discovering that the unstable amorphous mass of the longer chain xanthates can be used directly in the form as produced in the reactions, which obviates the need for the xanthates to first undergo expensive and/or time consuming treatments to purify and/or isolate the selected xanthates needed to make the new thionocarbamates thereby improving the efficiency of the processes and thus, making the use of the longer chain thionocarbamates having more than 4 carbon atoms as collectors more economically attractive.

As part of the investigation into the manufacture of the new thionocarbamates using the new xanthates, further investigations into the use of amines were conducted, such as for example, investigations into the effect of the reaction of amines with xanthates including both established amines and amines not previously investigated for use in making thionocarbamates, particularly thionocarbamates having the potential to be effective collectors of minerals.

Accordingly, it is an aim of the present invention to provide new thionocarbamates.

Accordingly, it is an aim of the present invention to provide new thionocarbamates that can be used as collectors in froth flotation processes to recover minerals of economic value.

Accordingly, it is an aim of the present invention to provide a blend of one or more thionocarbamates suitable for use as collectors in froth flotation processes.

Accordingly, it is an aim of the present invention to provide an improved synthetic route for using xanthates having substituents of 5 or more carbon atoms to make thionocarbamates having substituents of 5 or more carbon atoms.

Accordingly, it is an aim of the present invention to provide amines, including established amines and amines not previously used, which are useful in reactions with xanthates to prepare thionocarbamates having substituents of 5 or more carbon atoms.

Accordingly, it is an aim of the present invention to provide xanthates having substituents of 5 or more carbon atoms which are useful in making thionocarbamates.

Accordingly, it is an aim of the present invention to provide an improved synthetic route for making xanthates having substituents of 5 or more carbon atoms.

SUMMARY OF THE INVENTION

According to one form of the present invention, there is provided a thionocarbamate compound selected from methylisobutylcarbinolethyl thionocarbamate isopropylpropyl thionocarbamate amylpropyl thionocarbamate isopropyldibutyl thionocarbamate amyldibutyl thionocarbamate methylisobutylcarbinoldibutyl thionocarbamate methylisobutylcarbinolbenzyl thionocarbamate amylcyclohexyl thionocarbamate ethyldicyclohexyl thionocarbamate isopropyldicyclohexyl thionocarbamate isobutyldicyclohexyl thionocarbamate amyldicyclohexyl thionocarbamate ethyloctyl thionocarbamate isopropyloctyl thionocarbamate isobutyloctyl thionocarbamate amyloctyl thionocarbamate ethylethylhexyl thionocarbamate isopropylethylhexyl thionocarbamate isobutylethylhexyl thionocarbamate amylethylhexyl thionocarbamate isopropylethyldiamine thionocarbamate ethylhexyldibutyl thionocarbamate isobutylcyclohexyl thionocarbamate methylisobutylcarbinolcyclohexyl thionocarbamate ethylhexylcyclohexyl thionocarbamate methylisobutylcarbinoloctyl thionocarbamate ethylisooctyl thionocarbamate isobutylisooctyl thionocarbamate isopropylisooctyl thionocarbamate amylisooctyl thionocarbamate methylisobutylcarbinolisooctyl thionocarbamate ethylhexadecyl thionocarbamate methylisobutylcarbinolhexadecyl thionocarbamate ethylhexylhexadecyl thionocarbamate ethylaniline thionocarbamate isopropylaniline thionocarbamate ethylhexylethylhexyl thionocarbamate amylmethyl thionocarbamate isobutylpropyl thionocarbamate isobutylmethyl thionocarbamate

According to one form of the present invention, there is provided a process for making a thionocarbamate compound selected from: amylethyl thionocarbamate methylisobutylcarbinolethyl thionocarbamate amylpropyl thionocarbamate isobutylamyl thionocarbamate amylbutyl thionocarbamate ethyldibutyl thionocarbamate isopropyldibutyl thionocarbamate isobutyldibutyl thionocarbamate amyldibutyl thionocarbamate methylisobutylcarbinoldibutyl thionocarbamate ethylbenzyl thionocarbamate isopropylbenzyl thionocarbamate isobutylbenzyl thionocarbamate amylbenzyl thionocarbamate methylisobutylcarbinolbenzyl thionocarbamate ethylphenyl thionocarbamate isopropylphenyl thionocarbamate isobutylphenyl thionocarbamate amylphenyl thionocarbamate ethylcyclohexyl thionocarbamate isopropylcyclohexyl thionocarbamate isobutylcyclohexyl thionocarbamate amylcyclohexyl thionocarbamate ethyldicyclohexyl thionocarbamate isopropyldicyclohexyl thionocarbamate isobutyldicyclohexyl thionocarbamate amyldicyclohexyl thionocarbamate ethyloctyl thionocarbamate isopropyloctyl thionocarbamate isobutyloctyl thionocarbamate amyloctyl thionocarbamate ethylethylhexyl thionocarbamate isopropylethylhexyl thionocarbamate isobutylethylhexyl thionocarbamate amylethylhexyl thionocarbamate ethylhexyldibutyl thionocarbamate methylisobutylcarbinolcyclohexyl thionocarbamate ethylhexylcyclohexyl thionocarbamate methylisobutylcarbinoloctyl thionocarbamate methylisobutylcarbinolethylhexyl thionocarbamate ethylisooctyl thionocarbamate isobutylisooctyl thionocarbamate isopropylisooctyl thionocarbamate amylisooctyl thionocarbamate methylisobutylcarbinolisooctyl thionocarbamate ethylhexadecyl thionocarbamate methylisobutylcarbinonhexadecyl thionocarbamate ethylhexylhexadecyl thionocarbamate ethylaniline thionocarbamate isopropylaniline thionocarbamate methylisobutylcarbinolhexyl thionocarbamate ethylhexylethylhexyl thionocarbamate isoamylethyl thionocarbamate isobutylpropyl thionocarbamate isobutylbutyl thionocarbamate isobutylmethyl thionocarbamate comprising at least the steps of contacting a xanthate or xanthate containing material with an amine or amine-containing material in the presence of an acid material to form the thionocarbamate compound.

One embodiment includes a process for the production of a thionocarbamate comprising reacting a xanthate having a substituent attached to the oxygen atom of 5 or more carbon atoms with an amine in the presence of a carboxylic acid at a high temperature for a period of time sufficient to form a thionocarbamate having a substituent of 5 or more carbon atoms attached to the oxygen atom of the thionocarbamate and recovering and/or isolating the thionocarbamate from the reaction mixture to produce the thionocarbamate in a form suitable for use as a collector or for being converted into a collector for use in froth flotation processes in which the substituent is a linear, branched, unsubstituted, substituted, saturated, unsaturated, cyclic, heterocyclic, aliphatic, aromatic radicals, or the like.

According to embodiments, there is provided a process for the concentration of a mineral in a froth flotation installation comprising comminuting an ore containing the mineral to a size at which the desired mineral or minerals are at least partially liberated or accessible by a collector composition, contacting the comminuted mineral with the collector composition wherein, the collector composition comprises at least one thionocarbamate which is the reaction product of contacting a xanthate having a substituent that is attached to the oxygen atom of the xanthate which has 5 or more carbon atoms, with an amine in the presence of a an organic acid or organic acid salt to form the thionocarbamate wherein the thionocarbamate corresponds to the xanthate and has a substituent attached to the oxygen atom of the thionocarbamate, which substituent has 5 or more carbon atoms and is selected from linear branched, unsubstituted, substituted, cyclic, heterocyclic, aliphatic, aromatic radicals or the like.

According to one form, there is provided a method of extracting a mineral from a mineral containing material using a thionocarbamate comprising the steps of mixing an ore material containing the mineral with a collector containing at least one thionocarbamate in a froth flotation process such that the mineral is extracted from the ore material wherein the thionocarbamate is a compound of General Formula II:

RiOC(=S)NR2R3 (II) in which at least one of Ri, R2, or R3 is selected from a generally hydrocarbon radical having 5 or more carbon atoms and the others of Ri, R2, or R3are the same or different from each other wherein Ri, R2, and R3 are each a hydrocarbon radical selected from linear radicals, branched radicals, saturated radicals, unsaturated radicals, unsubstituted radicals, substituted radicals, cyclic radicals, heterocyclic radicals, aliphatic radicals, aromatic radicals, saturated radicals, unsaturated radicals or the like.

Forms of methods include using a xanthate of General Formula III RO CS2M (III) in which R is generally a hydrocarbon radical having 5 or more carbon atoms selected from linear radicals, branched radicals, saturated radicals, unsaturated radicals, unsubstituted radicals, substituted radicals, cyclic radicals, heterocyclic radicals, aliphatic radicals, aromatic radicals, saturated radicals, unsaturated radicals or the like.

Forms of methods include using an amine capable of reacting with a xanthate material to form a thionocarbamate compound having a substituent with 5 or more carbon atoms, wherein the thionocarbamate material is suitable for use as a collector for recovering a mineral of economic worth in a froth flotation process such that the use of the thionocarbamate in the froth flotation process improves the yield or amount of mineral recovered in the process, and/or the selectivity of the collector for the mineral being recovered in the process thereby improving the efficiency of using the thionocarbamate in the process.

According to one form, there is provided an amine capable of reacting with a xanthate material to form a thionocarbamate compound having at least one substituent on either the oxygen atom or nitrogen atom or both, of the thionocarbamate in which the substituent has 5 or more carbon atoms.

BRIEF DESCRIPTION OF EMBODIMENTS

THIONOCARBAMATES

It is to be noted that the substituents having 5 or more carbon atoms includes one of the substituents only or the total number of carbon atoms of all of the substituents represented by Ri and R3. Preferably, the single substituent only has the 5 or more carbon atoms so that at least one of Ri, R2 or R3 is a substituent with more than 5 carbon atoms.

In some forms, the thionocarbamate has two substituents each having 5 or more carbon atoms.

Typically, the substituents having 5 or more carbon atoms, typically include substituents with 6, 7, 8, 9, 10 or more carbon atoms, such as for example, hexyl, heptyl, octyl, aryl or the like including isomers of such substituent radicals, phenyl, cyclohexyl radicals or the like.

Typical examples of thionocarbamates having substituents of 5 or more carbon atoms include the thionocarbamates shown in Table 1 in which the substituent is derived from the xanthate only, or the amine only, or from a combination of the xanthate and amine. The examples shown in Table 1 include the following: isopropylmethyl thionocarbamate ethyldimethyl thionocarbamate isopropyldimethyl thionocarbamate isobutyldimethyl thionocarbamate ethylethyl thionocarbamate isopropylethyl thionocarbamate isobutylethyl thionocarbamate amylethyl thionocarbamate methylisobutylcarbinolethyl thionocarbamate isobutyldiethyl thionocarbamate ethylpropyl thionocarbamate isopropylpropyl thionocarbamate amylpropyl thionocarbamate isobutylamyl thionocarbamate ethylbutyl thionocarbamate isopropylbutyl thionocarbamate isobutylbutyl thionocarbamate amylbutyl thionocarbamate ethyldibutyl thionocarbamate isopropyldibutyl thionocarbamate isobutyldibutyl thionocarbamate amyldibutyl thionocarbamate methylisobutylcarbinoldibutyl thionocarbamate ethylbenzyl thionocarbamate isopropylbenzyl thionocarbamate isobutylbenzyl thionocarbamate amylbenzyl thionocarbamate methylisobutylcarbinolbenzyl thionocarbamate ethylphenyl thionocarbamate isopropylphenyl thionocarbamate isobutylphenyl thionocarbamate amylphenyl thionocarbamate ethylcyclohexyl thionocarbamate isopropylcyclohexyl thionocarbamate isobutylcyclohexyl thionocarbamate amylcyclohexyl thionocarbamate ethyldicyclo thionocarbamate isopropyldicyclo thionocarbamate isobutyldicyclo thionocarbamate amyldicyclo thionocarbamate ethyloctyl thionocarbamate isopropyloctyl thionocarbamate isobutyloctyl thionocarbamate amyloctyl thionocarbamate ethylethylhexyl thionocarbamate isopropylethylhexyl thionocarbamate isobutylethylhexyl thionocarbamate amylethylhexyl thionocarbamate isopropylethyldiamine thionocarbamate

The examples shown in Table 2 include the following: ethyldibutyl thionocarbamate methylisobutylcarbinoldibutyl thionocarbamate ethylhexyldibutyl thionocarbamate ethylcyclohexyl thionocarbamate isobutylcyclohexyl thionocarbamate isopropylcyclohexyl thionocarbamate amylcyclohexyl thionocarbamate methylisobutylcarbinolcyclohexyl thionocarbamate ethylhexylcyclohexyl thionocarbamate dicyclohexyl xanthate ethyloctyl thionocarbamate isobutyloctyl thionocarbamate isopropyloctyl thionocarbamate amyloctyl thionocarbamate methylisobutylcarbinoloctyl thionocarbamate ethylethylhexyl thionocarbamate isobutylethylhexyl thionocarbamate isopropylethylhexyl thionocarbamate amylethylhexyl thionocarbamate methylisobutylcarbinolethylhexyl thionocarbamate ethylisooctyl thionocarbamate isobutylisooctyl thionocarbamate isopropylisooctyl thionocarbamate amylisooctyl thionocarbamate methylisobutylcarbinolisooctyl thionocarbamate ethylhexadecyl thionocarbamate methylisobutylcarbinonhexadecyl thionocarbamate ethyI h exyI hexadecyl th ionocarbamate ethylbenzyl thionocarbamate isobutylbenzyl thionocarbamate isopropylbenzyl thionocarbamate amylbenzyl thionocarbamate ethylaniline thionocarbamate ethylphenyl thionocarbamate isopropylaniline thionocarbamate isopropylphenyl thionocarbamate

Preferred examples of the thionocarbamates include the following.

In respect of recovery of copper from samples of materials containing copper, the following compounds demonstrate superior suitability as collectors in froth flotation processes.

Copper only:

Reagent No. Name 42a ethylcyclohexyl thionocarbamate 51 methylisobutylcarbinolhexyl thionocarbamate 61a ethylhexylethylhexyl thionocarbamate 135 amylbenzyl thionocarbamate 151 amylmethyl thionocarbamate

The following compounds demonstrate superior suitability as collectors for copper and gold in combination in froth flotation processes:

Reagent No. Name 113 ethylbutyl thionocarbamate 135 amylbenzyl thionocarbamate 153 isopropylbutyl thionocarbamate 154 isoamylethyl thionocarbamate

The following compounds demonstrate superior suitability as collectors for gold, either alone or in combination with other minerals, particularly copper in froth flotation processes.

Reagent No. Name 100 isopropylbenzyl thionocarbamate 106 amylethyl thionocarbamate 113 ethylbutyl thionocarbamate 117 ethylbenzyl thionocarbamate 119 isobutylpropyl thionocarbamate 121 methylisobutylcarbinolethyl xanthate 125 isobutylbutyl thionocarbamate 126 isobutylbenzyl thionocarbamate 133 amylbutyl thionocarbamate 135 amylbenzyl thionocarbamate 138 amylphenyl thionocarbamate 150 isobutylmethyl thionocarbamate 151 amylmethyl thionocarbamate

It is to be noted that the reagent number associated with each of the above indicated compounds corresponds to the number used in providing the results of tests conducted to determine the commercial efficiency of selected thionocarbamates as collectors as shown in Tables 5 to 7 under the heading “Reagent” in these Tables.

Methods of making thionocarbamates

One form of the method and process of making the thionocarbamate includes:

Generally, one form of a reaction scheme in accordance with the present invention is provided in general formula IV which comprises contacting a suitable xanthate (identified as compound (1) above), and a suitable amine (compound (2)) in the presence of a carboxylic acid (compound (3)) and an alkaline material (compound (4)), such as for example, sodium carbonate to form the corresponding thionocarbamate (compound (5)) and a thioglycolate (compound (6)). Optionally, other materials or additives are included in the reaction between the xanthate and the amine to perform a variety of functions as required in accordance with the particular xanthate and/or amine selected and the reaction conditions.

It is to be noted that other reaction schemes are possible.

The reaction between the xanthate, amine and acid of general type IV above, is a single step reaction in which all components are present at the same time in a single reactor or alternatively, is a two-step or three-step or more step reaction in which two of the reactants react with each other at least partially prior to the addition of a third and/or subsequent reactant. In one form, the xanthate and amine react with each other before the acid is added to the reactor. In one form, the xanthate and acid react with each other before the amine is added to the reactor. It is to be noted that the reactants can be added to each other in any combination and/or in any order.

In general, one form of the process can be represented by the chemical reaction equation indicated above in General Formula IV, wherein (1) is a suitable xanthate, such as for example, the metal salt of the xanthate, particularly, the potassium or sodium salt, FtiOCSaM or the Xanthate ester (where M=R’ such as R1OC(=S)SR’), (2) is a suitable amine, (5) is the thionocarbamate produced in the reaction and (6) is a thioglycolate salt produced as a by-product in the reaction. It is to be noted that the thionocarbamate produced in the reaction corresponds partially to the xanthate and partially to the amine from which the thionocarbamate is produced in the reaction of the present invention. The acid (3) may typically be an organic acid, such as for example, chloroacetic acid (X = Cl) or may be an organic acid salt or the like. In other forms, other acid materials, such as for example, other carboxylic acids may be used as discussed below and/or elsewhere in this specification, such as for example, chloroacetic acid sodium salt, acetic acid, dichloroacetic acid, and the like.

In addition the use of diamino alkyl, triamino alkyl and tetramino alkyl amines may give compounds of formulae (7,8 and 9) which are di (7) and tri (8) and (9) thionocarbamte adducts. Such compounds could be prepared from ethylenediamine (where n= 2, yi= 1 for (7)), diethylene triamine (n=2, yi= 1 for (8)) and triethylene tetramine (n=2, yi=1 for (9)). Other amines could be used (n = 3,4, 5 etc). In addition polyamines (y1= 2,3, 4 etc, such as for example, diethylene triamine etc)could also be used. In addition, diaminocyclic compounds could also be used (piperazine, diazabycyclooctane and related compounds).

Similarly, diols may make dixanthates (compound (10)) which can also form dithionocarbamate adducts (compound (11)). Such compounds could be prepared from ethylene glycol (n=2, yi=1). Other diols could be used (n = 3,4, 5 etc). In addition glycols could also be used where (y1= 2,3, 4 etc, eg diethylene glycol etc)

Macrocyclic compounds may also be prepared by combination of dixanthates (from diols) and diamines or triamines. Some examples may be the macrocycles formed such as (compound (12)) where ni=n2=2 , y1 = y2= 1 prepared from ethylene glycol and ethylene diamine. Varied ring compounds where n1 and n2 = 1,2,3 etc may also be prepared. In addition glycols could also be used where (y1= 2,3, 4 etc, eg diethylene glycol etc) and poly amines (y2= 2,3, 4 etc, eg diethylene triamine, etc)

Similarly, use of more complex amines such as for example, diethylene triamine may give compounds such as (compound (13)) where R = CH2NH2.

A list of thionocarbamates made in accordance with forms of the present invention is provided in Tables 1,2 and 3, with preferred thionocarbamates being disclosed in Tables 1 and 2. It is to be noted that Table 3 is a list of representative thionocarbamates which is not meant to be an exhaustive list of possible thionocarbamates.

The reaction can be carried out in two or more batches in the same or in multiple reactors in which one reaction or set of reactions, occurs in one reactor before further reactants are added to the reactor for subsequent reactions occurring in the same reactor or separate reactions occur in separate reactors which are then combined into one of the reactors.

The thionocarbamates made from corresponding xanthates in accordance with the methods and processes as described herein can be used singly or in combination with one or more other thionocarbamates, including other thionocarbamates made in accordance with the described processes or methods or other currently available thionocarbamates, as mixtures, blends, combinations or the like. In other forms, the thionocarbamates or mixtures of thionocarbamates can be mixed with other types of collector compounds, activators, frothers and the like to form mixed type collectors.

Typically, one form of a blend is a mixture of isopropyl ethyl thionocarbamate with one or more thionocarbamates made in accordance with the described methods or processes having at least one substituent with 5 or more carbon atoms, or the total number of carbon atoms of the substituents being 5 or more. Other forms of blends include isobutyldiethyl thionocarbamate (IBDETC) and ethylpropyl thionocarbamate (EPTC) as an example of a mixture of thionocarbamate made in accordance with the described method or process. Other thionocarbamates include nAMTC, isoamylethyl thionocarbamate (¡AETC), methylisobutyl carbinol ethyl thionocarbamate (MIBCETC), isopropyl propyl thionocarbamate (iPPTC), isopropylisopropyl thionocarbamate (IPIPTC), isobutylallyl thionocarbamater (iBATC), isobutylpropyl thionocarbamate (¡BPTC), isobutylmethyl thionocarbonate (¡BMTC), isopropylmethyl thionocarbamate (iPMTC), isopropylbutyl thionocarbamate (iPBTC) and similar.

In one form, the collectors can be made by mixing or blending thionocarbamates as described having a substituent of 5 or more carbon atoms with other types of collectors, activators, frothers or similar, including dithiophosphates, monothiophosphates, octyl sulphides, salts and esters of mercaptobenzothiazoles, dithiocarbamates, trithiocarbamates, hydroxamates, or the like.

XANTHATES

Typically in one form, suitable xanthate salts are produced by the reaction of an alcohol with sodium or potassium hydroxide and carbon disulphide according to the reaction, such as for example, ROH+CS2+KOH—►ROCS2K+H20. (VI)

Typically, the xanthates have the following formula:

HSC(S)OR where R is a radical having 5 or more carbon atoms, including long chain and branched chain alkyl radicals and isomers thereof, including substituted, unsubstituted, saturated and unsaturated radicals, cylic, heterocyclic, aliphatic, aromatic or the like.

In one form, suitable xanthates useful for the manufacture of thionocarbamates include xanthates made by reacting alcohols containing more than four carbon atoms with carbon disulphide. In one example, the alcohol is amyl alcohol, hexyl alcohol or similar. In other forms, the alcohol could be any suitable alcohol for forming suitable xanthates which can be converted to thionocarbamates having substituents with five or more carbon atoms.

Typical examples of suitable xanthates include sodium salts of xanthates, such as for example, hexyl xanthates, octyl xanthates and the like, including the potassium salts and sodium salts of the xanthates, such as potassium amyl xanthate (PAX)

It is to be noted that a single xanthate can be used or a mixture of two or more xanthates can be used to form the corresponding thionocarbamate having at least one substituent of 5 or more carbon atoms.

AMINE

The use of the term amine is not meant to be limiting of the scope of the invention to monoamines or the like, but is more extensive in scope so as to include all types of amines. The term amine is used for clarity of expression and ease of understanding.

It is to be noted that any suitable amine can be used in the reaction of the invention.

In addition, the use of the term amine is not restricted to monoamines only, but also includes secondary amines, such as diamines, tertiary amines such as triamines, and other complex amines.

The amine can be a branched amine, a substituted amine, a monoamine, a diamine, a triamine, a primary amine, a secondary amine, a tertiary amine, a linear amine, a branched amine, a mixed amine, or a combination of two or more amines, an unsubstitued amine, a ring containing amine, an aliphatic amine, an aromatic amine, an amine substituted with a hetero atom, including an aliphatic ring or aromatic ring having the hetero atom either as part of the base structure of the amine or as part of one or more of the substituents of the amine.

In one form, the nitrogen of the amine is part of the ring structure of the amine, either an aliphatic ring or aromatic ring.

The amine can be a simple amine, a complex amine, an unsubstituted amine, a substituted amine or the like. In one form, the amine comprises carbon, nitrogen and hydrogen atoms only. In other forms, the amine can additionally include a hetero atom, such as O, S, P or the like.

Typical examples of suitable amines are provided in Table 4. A list of amines in accordance with one or other form of the methods, processes and/or reaction schemes of the invention is provided in Table 4. The list of compounds of Table 4 is representative of the types of amines useful in the present invention, and is not exhaustive.

In some forms, two or more different amines can be used to react with the xanthate or two or more xanthates to form the desired thionocarbamate. The two or more amines can be added separately or together in combination. The two or more amines can be added at different times in the reaction or in different steps or stages of the reaction.

ORGANIC ACID

Any suitable organic acid or organic acid salt can be used in the reaction or reactions to form the new thionocarbamates.

Typically, the organic acid is a carboxylic acid. More typically, any suitable carboxylic acid or carboxylic acid salt can be used in the process.

In one form, the carboxylic acid is a mono-acid, a diacid, a triacid or the like. The acid can be an unsubstituted acid or a substituted acid.

In one form, the carboxylic acid is an acetic acid, including an unsubstituted acid or a substituted acid. The acetic acid can be a mono-substituted, di-substituted, or tri-substituted acetic acid.

In one form, the acetic acid is a halogen substituted acetic acid. Typically, the substituted acetic acid is a monohalo-, dihalo-, trihalo- substituted acetic acid. If the acid contains more than a single halogen, the halogens can be the same or different. The halogen is typically chlorine. A particularly preferred halo-substituted acetic acid is monochloroacetic acid.

In one form, the acid is added in a single dose or in two or more separate doses.

The acid can be added in one reaction step, in two or more reactions steps or the like. A carbonate salt may be added to the reaction, for example, when an organic acid is used.

ADDITIVES

Other materials are optionally added to the reaction as required for a variety of purposes, such as buffers, and/or solvents or the like.

MINERAL MATERIALS

The thionocarbamates made in accordance with methods and processes of the invention can be used to treat a range of materials such as ores, pulps, slags, virgin material, previously treated material, minerals, tailings, waste materials, or the like to recover and/or extract a range of materials of economic importance which include gold, silver, platinum, copper, nickel, lead, palladium, zinc, molybdenum, bismuth or similar. Optionally, the selected thionocarbamate used as the collector in the froth flotation processes also rejects iron by not substantially simultaneously recovering iron so that the selectivity of the collector is improved with respect to the specific mineral being recovered.

The sample being treated, such as for example, the ore or similar being treated to recover the mineral or metal contained therein is reduced in size prior to contact with the collector. In one form, the ore is communited using suitable devices or the like, such as for example, a stamping installation with a plurality of stamping hammers, a ball mill or other device. The purpose of comminution is to reduce the particle size of the ore to a size at which the individual minerals contained within the ore can be partially, or almost entirely accessible by the thionocarbamate collectors to liberate the minerals from the surrounding gangue.

COLLECTORS

The thionocarbamates made by the described reaction can be used alone or in combination with other thionocarbamates, including other thionocarbamates made by the reaction of this invention, or thionocarbamates made by other reactions. Additionally, the collectors can include other materials for a variety of purposes to enhance the collection properties of the collector. Other materials include dithiophosphates, monothiophosphates, hydroxamates, octylsulphides, salts of mercaptobenzothiozoles or the like in any range and/or in any combination. A preferred collector composition is a blend of collector materials or components, including a blend of new thionocarbamates with other new thionocarbamates, new thionocarbamates with existing thionocarbamates, and new thionocarbamates with non thionocarbamates.

Collectors containing thionocarbamates in accordance with the present invention can be used in connection with a range of minerals, including but not limited to copper, gold, copper in combination with gold, silver, or the like. Optionally, the thionocarbamates are selective by simultaneously rejecting iron so as to be more selective in recovering the wanted mineral, i.e. improved selectivity as well as recovering increased amounts of the selected mineral, i.e. improved yield.

Typically, results that were successful against the control (standard Isopropyl Ethyl Thionocarbamate) are list below in three categories Copper Improved result over the standard,

Gold Improved results over the standard,

Both Copper & Gold Improved results over the standard.

As a reference point, the standard Isopropyl Ethyl Thionocarbamate (type 1) results are as follows (test 108);

Cu recovery 79.96%

Au recovery 67.01%

Fe recovery 31.00% (lower recovery is usually good on this parameter.. .with the exception of some gold operations) 1) Copper Improved result over standard (Cu/Fe) 123-81.67/36.6 154-83.82/36.36 156-82.31/17.34 164-83.15/27.78 42A-82.86/15.88 131 -81.50/26.63 2) Gold Improved results over the standard (Au/Fe) 119-77.95/33.09 121 -70.49/25.85 125-78.39/30.63 133-70.07/24.91 138-76.18/31.08 3) Both Copper & Gold Improved results over the standard (Cu/Au/Fe) 106-80.68/72.49/40.22 113-82.09/81.21/40.33 117-85.03/88.13/50.99 150-84.20/88.40/47.53 151 -86.59/82.64/47.49 100-84.70/80.10/41.45 135-84.81/76.17/35.14 126-87.72/88.75/52.80

Tests conducted using different thionocarbamates as the collectors in froth flotation processes of different minerals, most notably copper, gold and copper/gold in combination, are provided in the following Tables which provide information about the test results of a selection of thionocarbamates obtained from treating samples of ores when recovering selected minerals such as gold, copper or gold and copper in combination whilst rejecting iron.

Table 5 provides information about the amount of copper recovered using selected thionocarbamates compared to a standard identified in dark grey.

Table 6 provides information about the amount of gold alone recovered using selected thionocarbamates compared to a standard identified in dark grey.

Table 7 provides information about the amount of gold and copper recovered together using selected thionocarbamates compared to a standard identified in dark grey.

As can be readily seen from Tables 5 to 7, particularly Table 6, the thionocarbamates of the present invention have superior performance than the standard when recovering gold alone. Thus, the results of Tables 5 to 7 show that thionocarbamates having a single substituent with five or more carbon atoms have improved performance as collectors for recovering greater amounts of copper and/or gold in the samples tested, i.e. enhanced yield, and are more discriminating by simultaneously substantially rejecting iron, i.e. enhanced selectivity than does the standard used for comparison.

EXAMPLES

Aspects of forms of the invention will now be described with reference to the following example.

Example 1

One example of the reaction scheme in accordance with one form of the invention is along the following lines for the manufacture of the thionocarbamate from reacting a xanthate with an amine.

In a glass lined 100 litre reactor, monochloroacetic acid and sodium carbonate or sodium hydroxide or anhydrous sodium carbonate (soda ash), are combined under conditions of high temperature and pressure to initiate the reaction to form sodium monochloroacetate. As this reaction is substantially exothermic, cooling is required to control the rate of reaction, particularly in hot weather conditions in order to slow the reaction to enable the reaction to go to completion.

Subsequently, the sodium monochloroacetate is combined with the xanthate to form the corresponding sodium xanthate salt. In the event that NaOH had been used, cooling water is required to control the rate of reaction.

The sodium xanthate is then combined with the selected amine, such as for example, dimethyl amine, or diethyl amine, to complete the reaction scheme in which the reaction product is a more or less a homogeneous mass which includes the corresponding thionocarbamate (compound (5)), sodium thioglycolate (compound (6)) and sodium chloride in aqueous solution.

The selected amine is added at a rate of 400 kg per 1000 kg of the reaction product of making the xanthate mass, i.e. the mass containing the sodium xanthate salt produce a mass containing the thionocarbamate sodium thioglycolate and sodium chloride solution in which the total amount thionocarbamate is .50 to 50% of the mass.

The mass of reaction product is then separated into various phases by settling, typically by settling for about two hours in which the thionocarbamate rises to the surface of the settling tank to form a top layer. The top layer containing the thionocarbamate is removed from the settling tank.

The remaining layers undergo secondary separation for a duration of about 10 to 15 days, into two layers in the settling tank. The upper of the two layers includes small amounts of the thionocarbamate which is recovered from this layer.

The lower layer of the secondary separation containing sodium thioglycolate is separated for subsequent treatment and optionally undergoes further treatment, such as for example, refining the sodium thioglycolate into thioglycollic acid which is a marketable byproduct of the reaction forming the thionocarbamate.

In one form, the residues from the primary and secondary separation processes can undergo further treatments, such as for example, distillation, and/or further settling over periods of say, from 1 to 2 months, to recover additional amounts of thionocarbamate to improve the yield of the reactions, and hence the commercial acceptability of the thionocarbamates. In addition, the by-products of sodium thioglycolate and thioglycollic acid can be further treated, i.e. refined for use in formulating into useable compositions.

Typically, the selected thionocarbamate is present in the blend forming the collector composition in an amount in the range of about 1% to about 99%, typically in the range of about 5% to about 80%, preferably in the range of about 7% to 60%, more preferably, in the range of 10% to 40%, most preferably in the range of about 15% to 30%, by weight based on the total weight of the collector composition.

In one form, the dithiophosphate is a metal salt of dithiophosphate. In one form, the amount of dithiophosphate is from about 10% to 80% by weight of the total weight of the collector composition, preferably from about 25% to about 75%, more preferably from about 40% to 70%, and most preferably about 50% to 65%.

Preferably, the collector composition will have a 25 - 40% active dithiophosphate constituent.

ADVANTAGES

One advantage includes more of the target mineral or metal is able to be recovered using the new thionocarbamates made in accordance with the present invention either singly or in combination.

Another advantage is that less unwanted material is recovered along with the wanted material so that the thionocarbamate made in accordance with the invention are more selective in recovering the target mineral or metal.

The described arrangement has been advanced by explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination of features herein disclosed.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope. TABLE 1

LIST OF THIONOCARBAMATE SAMPLES

Dioctylamine and Diethylhexylamine - no products TABLE 2

Xanthate

Amine / = prepared China / = gram scale / - small trial scale TABLE 3

Possible Thionocarbamates

Table 3 continued

TABLE 4

Table 4 continued

Claims

CLAIMS:

1. A thionocarbamate compound selected from methylisobutylcarbinolethyl thionocarbamate isopropylpropyl thionocarbamate amylpropyl thionocarbamate isopropyldibutyl thionocarbamate amyldibutyl thionocarbamate methylisobutylcarbinoldibutyl thionocarbamate methylisobutylcarbinolbenzyl thionocarbamate amylcyclohexyl thionocarbamate ethyldicyclohexyl thionocarbamate isopropyldicyclohexyl thionocarbamate isobutyldicyclohexyl thionocarbamate amyldicyclohexyl thionocarbamate ethyloctyl thionocarbamate isopropyloctyl thionocarbamate isobutyloctyl thionocarbamate amyloctyl thionocarbamate ethylethylhexyl thionocarbamate isopropylethylhexyl thionocarbamate isobutylethylhexyl thionocarbamate amylethylhexyl thionocarbamate isopropylethyldiamine thionocarbamate ethylhexyldibutyl thionocarbamate isobutylcyclohexyl thionocarbamate methylisobutylcarbinolcyclohexyl thionocarbamate ethylhexylcyclohexyl thionocarbamate methylisobutylcarbinoloctyl thionocarbamate ethylisooctyl thionocarbamate isobutylisooctyl thionocarbamate isopropylisooctyl thionocarbamate amylisooctyl thionocarbamate methylisobutylcarbinolisooctyl thionocarbamate ethylhexadecyl thionocarbamate methylisobutylcarbinolhexadecyl thionocarbamate ethylhexylhexadecyl thionocarbamate ethylaniline thionocarbamate isopropylaniline thionocarbamate ethylhexylethylhexyl thionocarbamate amylmethyl thionocarbamate isobutylpropyl thionocarbamate isobutylmethyl thionocarbamate
2. A process for making a thionocarbamate compound selected from: amylethyl thionocarbamate methylisobutylcarbinolethyl thionocarbamate amylpropyl thionocarbamate isobutylamyl thionocarbamate amylbutyl thionocarbamate ethyldibutyl thionocarbamate isopropyldibutyl thionocarbamate isobutyldibutyl thionocarbamate amyldibutyl thionocarbamate methylisobutylcarbinoldibutyl thionocarbamate ethylbenzyl thionocarbamate isopropylbenzyl thionocarbamate isobutylbenzyl thionocarbamate amylbenzyl thionocarbamate methylisobutylcarbinolbenzyl thionocarbamate ethylphenyl thionocarbamate isopropylphenyl thionocarbamate isobutylphenyl thionocarbamate amylphenyl thionocarbamate ethylcyclohexyl thionocarbamate isopropylcyclohexyl thionocarbamate isobutylcyclohexyl thionocarbamate amylcyclohexyl thionocarbamate ethyldicyclohexyl thionocarbamate isopropyldicyclohexyl thionocarbamate isobutyldicyclohexyl thionocarbamate amyldicyclohexyl thionocarbamate ethyloctyl thionocarbamate isopropyloctyl thionocarbamate isobutyloctyl thionocarbamate amyloctyl thionocarbamate ethylethylhexyl thionocarbamate isopropylethylhexyl thionocarbamate isobutylethylhexyl thionocarbamate amylethylhexyl thionocarbamate ethylhexyldibutyl thionocarbamate methylisobutylcarbinolcyclohexyl thionocarbamate ethylhexylcyclohexyl thionocarbamate methylisobutylcarbinoloctyl thionocarbamate methylisobutylcarbinolethylhexyl thionocarbamate ethylisooctyl thionocarbamate isobutylisooctyl thionocarbamate isopropylisooctyl thionocarbamate amylisooctyl thionocarbamate methylisobutylcarbinolisooctyl thionocarbamate ethylhexadecyl thionocarbamate methylisobutylcarbinonhexadecyl thionocarbamate ethylhexylhexadecyl thionocarbamate ethylaniline thionocarbamate isopropylaniline thionocarbamate methylisobutylcarbinolhexyl thionocarbamate ethylhexylethylhexyl thionocarbamate isoamylethyl thionocarbamate isobutylpropyl thionocarbamate isobutylbutyl thionocarbamate isobutylmethyl thionocarbamate comprising at least the steps of contacting a xanthate or xanthate containing material with an amine or amine-containing material in the presence of an acid material to form the thionocarbamate compound.
3. A process for making a thionocarbamate compound according to claim 1 comprising at least the steps of contacting a xanthate or xanthate containing material with an amine or amine-containing material in the presence of an acid material to form the thionocarbamate compound.
4. A process for the preparation of a thionocarbamate compound according to claim 2 in which the step of contacting the xanthate or xanthate containing material and the amine is in the presence of an unsubstituted or substituted acetic acid to form the thionocarbamate.
5. A process for making a thionocarbamate compound according to claim 3 in which the step of contacting the xanthate or xanthate containing material and the amine is in the presence of an unsubstituted or substituted acetic acid to form the thionocarbamate.
6. A process for making a thionocarbamate compound according to claim 2 comprising reacting a xanthate having a substituent attached to the oxygen atom, which substituent has at least 5 carbon atoms with an amine in the presence of a carboxylic acid at an elevated temperature for a period of time sufficient to form the thionocarbamate having the substituent of at least 5 carbon atoms attached to the oxygen atom of the thionocarbamate and recovering and/or isolating the thionocarbamate from the reaction mixture to produce the thionocarbamate compound in a form suitable for use as the compound for incorporation into a collector composition or for being converted into a collector composition for use in froth flotation processes.
7. A process for making a thionocarbamate compound of claim 1 comprising reacting a xanthate having a substituent attached to the oxygen atom, which substituent has at least 5 carbon atoms with an amine in the presence of a carboxylic acid at an elevated temperature for a period of time sufficient to form the thionocarbamate having the substituent of at least 5 carbon atoms attached to the oxygen atom of the thionocarbamate and recovering and/or isolating the thionocarbamate from the reaction mixture to produce the thionocarbamate compound in a form suitable for use as the compound for incorporation into a collector composition or for being converted into a collector composition for use in froth flotation processes.
8. A collector composition for recovering a mineral in froth flotation processes comprising at least one thionocarbamate compound according to claim 1 or a thionocarbamate compound made by a process of any one of claims 2 to 7.
9. A collector composition according to claim 8 comprising a first thionocarbamate compound according to claim 1 or a thionocarbamate compound made by a process of any one of claims 2 to 7, a second thionocarbamate compound according to claim 1 or a thionocarbamate compound made by a process of any one of claims 2 to 7, and at least one other collector material wherein the other collector material is selected from a thionocarbamate compound different to the first and second thionocarbamate compounds, a dithiophosphate, a monothiophosphate, an octylsulphide, a salt or ester of a mercaptobenzothiozole, a dithiocarbamate, a trithiocarbamate, or a hydroxolamate.
10. A process for concentration of a mineral in a froth flotation installation comprising comminuting an ore containing the mineral to a size at which the desired mineral or minerals are at least partially liberated or accessible by the thionocarbamate compound of the collector composition according to claim 8 or 9 and contacting the comminuted mineral with the collector composition.
11. A process for the use of a compound according to claim 1 or a thionocarbamate compound made by a process of any one of claims 2 to 7 for extracting a mineral in a froth flotation installation in which the mineral is one or more of copper, gold, silver, platinum, nickel, molybdenum, cobalt, lead, palladium, zinc, or bismuth, either alone or in combination of two or more.
12. A process according to claim 11 in which the thionocarbamate compound is useful as a collector in froth flotation processes having enhanced selectivity for the mineral being concentrated.
13. A process according to claim 12 in which the thionocarbamate compound is useful as a collector in froth flotation processes having enhanced selectivity against recovering iron.
14. A process according to any one of claims 10 to 13 for recovering more than a single mineral.
15. A process according to any one of claims 10 to 14 in which the collector composition in froth flotation processes is for the simultaneous recovery of copper and gold.
16. A process according to any one of claims 10 to 15 in which the amount of the mineral being recovered is from about 60% to 95%.
17. A process according to claim 16 in which the amount of the mineral being recovered is from 67% to 88%.
18. A process according to claim 16 in which the amount of the mineral being recovered is from about 70% to 87%.
19. A process according to any one of claims 10 to 18 in which the material being treated to recover the mineral therefrom includes ores, pulps, slags, virgin material, previously treated material, previously treated minerals, tailings, or waste materials.