DE10006251A1 - S-Alkyl-, aryl- and -aralkyl-O-alkyl-dithiocarbonates are used as collectors in flotation of complex sulfide ores, especially copper, molybdenum, lead, zinc and nickel sulfide - Google Patents

Abstract

S-(1-8 carbon (C)-Alkyl-, aryl- and -aralkyl)-O-(1-18 C alkyl)-dithiocarbonates (I) are used as collectors in the flotation of complex sulfide ores. S-(1-8 carbon (C)-Alkyl-, aryl- and -aralkyl)-O-(1-18C alkyl)-dithiocarbonates of formula (I) are used as collectors in the flotation of complex sulfide ores: R1>-O-C(=S)-S-R (I) R1>1-18C alkyl; R : 1-18C alkyl, aryl or aralkyl.

Description

Raw materials for metal extraction are ores, which are mostly a mixture that in addition to the compounds of the metals to be extracted, there are also worthless minerals Gait, contains that have grown together with the ore minerals. This often comes with Mining collapsed rock. The purpose of the preparation is that Gait and bedrock, called mountains, as efficiently and economically as possible to separate. The separation of the ore minerals from the gangue by means of physical and physico-chemical processes, sorting, as The main task of processing assumes that the ore minerals and mountains differ significantly in certain physical properties. Still is Prerequisite that the raw ore is largely open to ore and Gait mineral that grow together in the same particle exist, cannot be physically separated. All Sorting procedures and facilities are only for processing a specific one Grain size range suitable.

Flotative separations are currently the most important processes for the fine to Fine grain sorting of non-ferrous metals. Without these processes, the usage would be many finely overgrown raw materials on today's technical and economic level unimaginable.

In the flotation process, the different mineral types can be separated can be achieved by adding various chemicals that Check the wettability of the individual minerals in the flotation slurry. This Due to their function, chemicals can be divided into the categories, namely collectors, Foamers, pushers, activators and modifiers can be classified.  

Collectors are reagents that are mainly used for the hydrophobization of the Value minerals worry. They are surface-active organic substances that work on the Surface of the mineral can be adsorbed. Collectors contain a polar functional group, because of their hydrophilicity with the mineral surface is connected, and a non-polar group, which due to its hydrophobicity to a Air bubble is tacked. The hydrophobic part of the collector is usually a Hydrocarbon residue. Collectors become either because of their functional Group or classified according to the type of mineral collected.

Important commercially available standard types are xanthates, dithiophosphates and Thionocarbamate (Schubert: Preparation of solid mineral raw materials, volume II, 1977, pp. 296ff). This is often achievable with these standard collectors Application and the selectivity completely unsatisfactory (e.g. when present complex mixer ores), so that special collector types are required.

US 4,793,852 discloses xanthates as collectors for sulfidic ores. This Xanthates carry an aromatic substitution on the oxygen atom of the Xanthate group.

Surprisingly, it has now been found that certain dithiocarbonates with aliphatic substitution at the oxygen atom is an excellent collector are.

The invention thus relates to the use of compounds of the formula (1)

wherein
R ^{1 is} an alkyl radical having 1 to 18 carbon atoms, and
R is an alkyl, aryl or aralkyl radical having 1 to 18 carbon atoms
as a collector in the flotation of complex sulfide ores.

R ¹ is preferably C ₂ to C ₆ alkyl, in particular isopropyl and R is a benzyl radical.

With this type of collector, improved results in selectivity and yield can be achieved in the flotation of non-ferrous metal sulfides compared to standard collectors. These new collectors can also be used in combination with standard collectors such as xanthates (2) and dithiophosphates (3), which have the following structure:

with R ² = C ₁ to C ₁₈ alkyl and Me = alkali metal, in particular K and Na;

with R ³ = alkyl, aryl with 1 to 18 carbon atoms and Me = alkali metal, in particular K and Na.

All metal sulfides (except Fe) can be floated, whereby Cu, Mo, Pb, Zn and Ni are particularly noteworthy. The Processing of Cu, Zn and Mo can be observed. The collector is in a wide range pH range applicable (2 to 12) and the aqueous turbidity in one Concentration between preferably 0.01 and 1.0 kg / ton added.

This reagent is used especially for complex Cu-containing mixed ores significant improvement in selectivity and output achieved.  

Examples 1. Preparation of S-benzyl-O-iso-propyldithiocarbonate

In a 2 l 4 neck flask with reflux condenser and stirrer
490 g (2.63 mol) Na isopropylxanthate (85%) and
600 g water
charged. The mixture is stirred for 15 min at room temperature, the xanthate e.g. T. is dissolved or dispersed. With stirring, now for about 30 minutes.
360 g (2.85 mol) of benzyl chloride
added, the reaction temperature rising to 40 to 50 ° C. When the addition is complete, the mixture is heated to 70 to 75 ° C. for 120 minutes. After cooling to 40-45 ° C, a two-phase mixture is obtained which can be separated in a separating funnel after 24 hours. The upper organic phase is dried, and 581.1 g (= 97.6% yield) of S-benzyl-O-iso-propyldithiocarbonate are obtained as a clear, yellow, oily liquid.

2. Preparation of S-Benzyl-O-Ethyldithiocarbonate

In a 2 l 4 neck flask with reflux condenser and stirrer
446.2 g (2.63 mol) Na ethyl xanthate (85%) and
600.0 g water
charged. The mixture is stirred for 15 minutes at the reaction temperature, the xanthate e.g. T. is dissolved or dispersed. With stirring, now for about 30 minutes.
360.0 g (2.85 mol) of benzyl chloride
added, the reaction temperature rising to 40 to 50 ° C. When the addition is complete, the mixture is heated to 70 to 75 ° C. for 120 minutes. After cooling to 40-45 ° C, a two-phase mixture is obtained which can be separated in a separating funnel after 24 hours. The upper organic phase is dried, and 540.0 g (= 96.7% yield) of S-benzyl-O-ethyldithiocarbonate are obtained as a clear, yellow, oily liquid.

3. Preparation of S-Benzyl-O-Amyldithiocarbonate

In a 2 l 4 neck flask with reflux condenser and stirrer
577.7 g (2.63 mol) Na amylxanthate (85%) and
600.0 g water
charged. The mixture is stirred for 15 minutes at the reaction temperature, the xanthate e.g. T. is dissolved or dispersed. With stirring, now for about 30 minutes.
360.0 g (2.85 mol) of benzyl chloride
added, the reaction temperature rising to 40 to 50 ° C. When the addition is complete, the mixture is heated to 70 to 75 ° C. for 120 minutes. After cooling to 40-45 ° C, a two-phase mixture is obtained which can be separated in a separating funnel after 24 hours. The upper organic phase is dried, and 625.0 g (= 93.5% yield) of S-benzyl-O-amyldithiocarbonate are obtained as a clear, yellow, oily liquid.

Application studies

example 1 S-benzyl-O-isopropyldithiocarbonate / Na-isopropylxanthate Example 2 S-benzyl-O-ethyldithiocarbonate / Na-isopropylxanthate Example 3 S-benzyl-O-amyldithiocarbonate / Na-isopropylxanthate Example 4 S-allyl-O-amyldithiocarbonate / Na-isopropylxanthate Example 5 Na isopropyl dithiophosphate / Na isopropyl xanthate Example 6 S-benzyl-O-benzyldithiocarbonate / Na-isopropylxanthate Example 7 S-benzyl-O-phenyldithiocarbonate / Na-isopropylxanthate Example 8 Isopropyl ethyl thionocarbamate / Na isopropyl xanthate

Claims (7)

1. Use of compounds of the formula (1)
wherein
R ^{1 is} an alkyl radical having 1 to 18 carbon atoms, and
R is an alkyl, aryl or aralkyl radical having 1 to 18 carbon atoms
as a collector in the flotation of complex sulfide ores. 2. Use according to claim 1, wherein R ^{1 is} C ₂ to C ₆ alkyl. 3. Use according to claim 1 and / or 2, wherein R is a benzyl radical stands. 4. Use according to one or more of claims 1 to 3, wherein in addition compounds of the formulas 2 and 3
with R ² = C ₁ to C ₁₈ alkyl and Me = alkali metal, in particular K and Na;
with R ³ = alkyl, aryl with 1 to 18 carbon atoms and Me = alkali metal,
especially K and Na can be used as co-collectors. 5. Use according to one or more of claims 1 to 4, wherein the Total concentration of collectors between 0.01 and 1.0 kg per ton of water Cloudy lies. 6. Use according to one or more of claims 1 to 5, wherein the pH is between 2 and 12. 7. Use according to one or more of claims 1 to 6 for Flotation of sulfides of the metals Cu, Mo, Pb, Zn and / or Ni.