GB2108870A

GB2108870A - Flotation of oxidic tin ores

Info

Publication number: GB2108870A
Application number: GB08231142A
Authority: GB
Inventors: Martin Becker; Christian Neuber; Alexander Rosenbaum; Heinz Seidel; Beate Voigt; Karl Lehmann; Klaus Puchner; Ekkehart Mosch
Original assignee: BERGBAU und HUTTENKOMBINAT ALB
Current assignee: BERGBAU und HUTTENKOMBINAT ALB
Priority date: 1981-11-04
Filing date: 1982-11-01
Publication date: 1983-05-25
Also published as: CS251219B1; AU8854782A; SU1457939A1; CS638982A1; DD221333A3; GB2108870B; AU557734B2

Abstract

In a method for the flotation of oxidic tin ores, fine-ground tin ore is converted into a suspension which is floated in the presence of a collecting and/or controlling and/or foaming agent, wherein the collecting agent is either (7) a biolipid extract and 2- phenylethylene-phosphonic acid or (2) a biolipid extract, a sodium soap of a biolipid extract and 2-phenylethylene- phosphonic acid or (3) biolipid extract fractions enriched with phosphatide or free fatty acid and 2-phenylethylene- phosphonic acid.

Description

SPECIFICATION Method for the flotation of oxidic tin ores The present invention is concerned with a method for the selective flotation of oxidic tin ores and especially of low-grade tin ores which are difficult to beneficiate and which contain many associated oxidic and sulphidic minerals.

Methods are already known for the flotation of low-grade oxidic tin ores which are difficult to beneficiate and which contain many different minerals, such as quartz, topaz, mica, feldspar, heamatite, chalcopyrite, arsenopyrite, bismuthinite, kaolin and the like. The beneficiation of such tin ores is difficult to perform and makes great demands on the selectivity of the flotation process.

One such known method consists in the flotation of fine-ground tin ore with the addition of 2phenylethylene phosphonic acid as collector, together with octandiol as a foaming agent (see German Democratic Republic Patent Specification No. 31537).

This method has the disadvantage of necessitating the grinding of the ore to a very high degree of fineness in order to achieve satisfactory results in the flotation process. This high degree of fineness is required because the upper grain size which is still capable of being floated with good results with 2phenylethylene-phosphonic acid lies in the range of fine grains with a particle size which is not greater than 0.063 mm.

However, as is well known, grinding cannot be controlled in such a way that the grain-size composition of the ground ore can be limited to the grain sizes which can still be floated. Since the coarser grain size fractions contained in the ground ore can only insufficiently be floated or not floated at all with 2-phenylethylene-phosphonic acid, the loss of the valuable components is still relatively high.

In addition, the necessary fine grinding results in high capital and energy costs. On the other hand, the collecting agent is expensive, which, particularly in the case of low-grade tin ores, results in high flotation costs because the production of a given quantity of concentrate requires a large throughput of ore and, consequently, also great amounts of collecting agents.

It is an object of the present invention to minimise the losses of valuable components in the flotation of tin ores which are difficult to beneficiate and to keep the consumption of expensive collecting agents, as well as capital and operational costs, at a low level.

When 2-phenylethylene-phosphonic acid is used as a collector for the flotation of oxidic tin ores, the upper grain size still capable of being floated with good results is not greater than 0.063 mm. This results in a relatively high loss of valuable components because the coarser grains contained in the flotation feed do not float at all or only to an insufficient extent.

Therefore, it is an object of the present invention to provide a method for the flotation of oxidic tin ores which allows the range of grain sizes capable of being floated successfully with 2-phenylethylene phosphonic acid to be increased.

Thus, according to the present invention, there is provided a method for the flotation of oxidic tin ores, wherein fine-ground tin ore is converted into a suspension which is floated in the presence of a collecting and/or controlling and/or foaming agent, wherein the collecting agent is either (1) a biolipid extract and 2-phenylethylene-phosphonic acid or (2) a biolipid extract, a sodium soap of a biolipid extract and 2-phenylethylene-phosphonic acid or (3) biolipid extract fractions enriched with phosphatide or free fatty acid and 2-phenylethylene-phosphonic acid.

The biolipid extract used according to the present invention is obtained as a by-product in the microbiological fermentation of hydrocarbons with yeasts or bacteria after extraction of the biomass with low-boiling solvents. The main components of the biolipid extract are lipids of microbiological origin containing fatty acids (such as phosphatides and glycerides), free fatty acids and other biogenous substances, which may be dissolved in a hydrocarbon fraction boiling, for example, in the temperature range of from 510 to 6500K.

The biolipid extract and the 2-phenylethylene-phosphonic acid can be mixed in a ratio of 1:0.2 to 1:1.5 and preferably in a ratio of 1:1. A biolipid extract containing up to 80% and preferably about 70% of sodium soap can be mixed with 2-phenylethylene-phosphonic acid in a ratio of 1:0.2 to 1:1.5 and preferably of 1:1.

The reagent mixture can be used in the form of an aqueous emulsion with the sodium soap of the biolipid extract acting as emulsifier or with an additional conventional emulsifier.

The method according to the present invention can be used for the flotation of oxidic tin ores which are difficult to beneficiate. It has the advantage of also allowing coarser grain-size fractions of fine-ground tin ore to be recovered, which results in an increase of the recovery of valuable components.

Furthermore, by the use of the above-described reagent mixture, the specific costs of reagents per tonne of throughput can be kept at a low level.

In addition, diminishing the percentage of phosphonic acid used results in a decrease of environmental pollution. The grinding process can be carried out under more favourable conditions because, due to the possibility of floating coarser grains, the lower limit of grain size can be raised.

The following Example is given for the purpose of illustrating the present invention: EXAMPLE The biolipid extract necessary for preparing the collector mixture is obtained as a by-product in the extract purification of a yeast (strain: Lodderomyces elongisporus) cultured on a petroleum distillate boiling in the temperature range of 510 to 6500K.

1 tonne of tin ore containing 0.3% tin and quartz, topaz, feldspar, haematite and mica as main components is ground to < 0.100 mm., suspended with water to give a pulp density of 1.7 kg./l. and treated with 250 g. disodium hexafluosilicate. After the water has been partially exchanged, the tincontaining components are floated with 200 g. of a collector mixture containing 50% 2-phenylethylenephosphonic acid and 50% biolipid extract, 100 g. of octandiol being used as foaming agent.

The collector mixture is preferably used in the form of an aqueous emulsion. Using part of the biolipic extract in the form of sodium soap helps in emulsifying the collector mixture. The percentage of the saponified product is 70%. The experimental results obtained with collector mixtures of biolipid extract and 2-phenylethylene-phosphonic acid mixture in various ratios are shown in the following Tablet Collector mixture (total amount added: 200 g/t)

2-phenyl- Bio- Concentrate Ratio of ethylene- lipid Feed c Sn Sn phosphonic extract a 1- ~ concentration recovery acid, % % % Sn % %Fe a::c 100 e Q 0.442 3.7 5.05 11.55 8.37 76.3 75 25 0.513 3.05 5.45 9.85 5.95 78.1 50 50 0.563 3.6 5.6 9.6 6.37 1 80.2 A considerable increase in tin recovery is accompanied by a lower concentration in the roughing stage. This can be compensated by cleaning stages.

Further experiments have shown that, with an increasing percentage of biolipid extract in the collector mixture, a slight decrease in concentration and recovery can be observed. However, the most unsatisfactory results have been obtained with a biolipid extract which is not mixed with 2phenylethylene-phosphonic acid.

With the use of, for example, 50% biolipid extract, the grain size of tin ore still floatabie can be increased: Sn recovery from the grain-size fractions, % (d ym)

0-40 40-63 63-100 100-160 | +160 Average 100% 2-phenyl ethylene- phosphonic acid 95.1 83.3 50.5 10.5 5.3 76.9 Mixture of 2 phenylethylene phosphonic acid and biolipid extract in the ratio 1: :1 94.8 84.0 51.7 17.8 8.6 80.6 The biolipid extract used as a component of the reagent mixture can also be replaced by extract fractions enriched either with phosphatides or with fatty acids.

It is also possible to add to the tin ore suspension a reagent mixture of biolipid extract with other tin ore collectors, for example arsenic acid, other phosphonic acids, sulphosuccinamates and carboxylic acids or of biolipid extract with foaming and controlling agents.

Claims

1. Method for the flotation of oxidic tin ores, wherein fine-ground tin ore is converted into a suspension which is floated in the presence of a collecting and/or controlling and/or foaming agent, wherein the collecting agent is either (1) a biolipid extract and 2-phenylethylene-phosphonic acid or (2) a biolipid extract, a sodium soap of a biolipid extract and 2-phenylethylene-phosphonic acid or (3) biolipid extractions enriched with phosphatide or free fatty acid and 2-phenylethylene-phosphonic acid.

2. Method according to claim 1, wherein the biolipid extract used is obtained as a by-product in the microbiological fermentation of hydrocarbons with yeasts or bacteria after extraction of the biomass with low-boiling solvents.

3. Method according to claim 1 or 2, wherein the biolipid extract and the 2-phenylethylenephosphonic acid are mixed in a ratio of 1:0.2 to 1:1.5.

4. Method according to claim 3, wherein the biolipid extract and the 2-phenylethylene-phosphonic acid are mixed in a ratio of 1:1.

5. Method according to claim 1 or 2, wherein the biolipid extract containing a percentage of its sodium soap and the 2-phenylethylene-phosphonic acid are mixed in a ratio of 1:0.2 to 1:1.5.

6. Method according to claim 5, wherein the biollipid extract and the 2-phenylethylenephosphonic acid are mixed in a ratio of 1:1.

7. Method according to claim 5 or 6, wherein the biolipid extract contains up to 80% of sodium soap.

8. Method according to claim 7, wherein the biolipid extract contains about 70% of sodium soap.

9. Method according to any of the preceding claims, wherein the collector mixture is used in the form of an aqueous emulsion in which the sodium soap of the biolipid extract acts as emulsifier.

1 0. Method according to any of the preceding claims, wherein an additional conventional emulsifier is used.

11. Method according to claim 1 for the flotation of oxidic tin ores, substantially as hereinbefore described and exemplified.

12. Oxidic tin ores, whenever recovered by the method according to any of claims 1 to 11.