CA1238192A - Method for the recovery of germanium - Google Patents
Method for the recovery of germaniumInfo
- Publication number
- CA1238192A CA1238192A CA000470878A CA470878A CA1238192A CA 1238192 A CA1238192 A CA 1238192A CA 000470878 A CA000470878 A CA 000470878A CA 470878 A CA470878 A CA 470878A CA 1238192 A CA1238192 A CA 1238192A
- Authority
- CA
- Canada
- Prior art keywords
- iron
- germanium
- leach
- solution
- amount
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B41/00—Obtaining germanium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G17/00—Compounds of germanium
Abstract
ABSTRACT OF THE DISCLOSURE
A process for the recovery of germanium includes acid leaching of germanium-containing oxidic material and neutralization to pH 3-5 in the presence of ferris iron, whereby a precipitate is obtained. The precipitate is releached in acid and the leach slurry is reduced with at least one reductant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron. Preferably, lead sulfide concentrate and iron are used in a two-step reduction following the reteach. Germanium in the reduced solution is precipitated as germanium sulfide. The use of lead or zinc sulfide concentrate and iron results in a reduction of arsenic and antimony in and a substantial elimination of copper from the germanium sulfide-containing concentrate.
A process for the recovery of germanium includes acid leaching of germanium-containing oxidic material and neutralization to pH 3-5 in the presence of ferris iron, whereby a precipitate is obtained. The precipitate is releached in acid and the leach slurry is reduced with at least one reductant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron. Preferably, lead sulfide concentrate and iron are used in a two-step reduction following the reteach. Germanium in the reduced solution is precipitated as germanium sulfide. The use of lead or zinc sulfide concentrate and iron results in a reduction of arsenic and antimony in and a substantial elimination of copper from the germanium sulfide-containing concentrate.
Description
- ~23~3~9~
This invention relates to a method for the recovery of germanium and, more particularly, to a method for the recovery of a germanium concentrate from oxidic zinciferous material.
Processes for the recovery of germanium from germanium - containing materials, which include germanium ores and concentrates, and from oxidic zinciferous materials usually have included a leach of the material, a conversion to germanium tetrachloride~ precipitation of germanium sulfide, conversion to germanium dioxide and the recovery of germanium from germanium oxide or recovery by cementation from solution with a metal such as zinc. According to one of such processes, oxidic zinciferous material is mixed with Hal, Joke is distilled off, HIS is passed through the distillate, the precipitate is purified, Gets is ignited and germanium is recovered as Joy (J. Am. Chum. So., 43, 2131-43, 1921).
According to a process described in the Engineering and Mining Journal, 157, 5, 83-85 (1965), blast furnace dust is baked with sulfuric acid, the sulfated material is leached, leach solution is oxidized with anode mud, arsenic is precipitated with crushed limestone and germanium is entrained by the absorbing action of copper hydrate. The germanium cake still contains considerable amounts of Zen, Cud, Cut and As. According to another process, described in the Engineering and Mining Journal, 157, 5, 88 (1956), oxidic zinciferous material is leached with sulfuric acid to dissolve zinc and cadmium and the leach residue containing As, Sub, Bit Cud, Sun and Go is leached in hot, strong sulfuric acid. Go, As and Cud are precipitated ~Z38~
from the leach solution as sulfides which are roasted and leached once more. The final cake is subjected to distillation to convert Go to Joke which is further purified and hydrolyzed to Joy. A similar process is disclosed in U.S.
Patent 2 929 677, which issued March 22, 1960, and according to which oxidic zinciferous material is leached with sulfuric acid a ferris salt and sodium hydroxide solution are added to the leach solution to precipitate iron and germanium compounds, the precipitated compounds are ground with sodium chloride, digested with sulfuric acid concurrently volatilizing Joke, Juicy is precipitated from Joke solution and Juicy is ignited to Joy.
One of the major problems in processes for the recovery of germanium from oxidic zinciferous materials is the presence of metals such as copper, cadmium, arsenic and antimony, which, if not eliminated, will contaminate the germanium sulfide.
We have now found that this problem can be alleviated by leaching oxidic zinciferous material in two stages and carrying out the second stage in such a way that at least a portion of the Cut As and Sub are removed in the leach residue.
Germanium sulfide is then precipitated in a relatively pure form, arsenic being the major contaminant. More specifically, oxidic zinciferous material is subjected to a leach in sulfuric acid to dissolve germanium into a leach solution which is neutralized in the presence of ferris iron whereby a germanium - containing precipitate is formed. This precipitate also
This invention relates to a method for the recovery of germanium and, more particularly, to a method for the recovery of a germanium concentrate from oxidic zinciferous material.
Processes for the recovery of germanium from germanium - containing materials, which include germanium ores and concentrates, and from oxidic zinciferous materials usually have included a leach of the material, a conversion to germanium tetrachloride~ precipitation of germanium sulfide, conversion to germanium dioxide and the recovery of germanium from germanium oxide or recovery by cementation from solution with a metal such as zinc. According to one of such processes, oxidic zinciferous material is mixed with Hal, Joke is distilled off, HIS is passed through the distillate, the precipitate is purified, Gets is ignited and germanium is recovered as Joy (J. Am. Chum. So., 43, 2131-43, 1921).
According to a process described in the Engineering and Mining Journal, 157, 5, 83-85 (1965), blast furnace dust is baked with sulfuric acid, the sulfated material is leached, leach solution is oxidized with anode mud, arsenic is precipitated with crushed limestone and germanium is entrained by the absorbing action of copper hydrate. The germanium cake still contains considerable amounts of Zen, Cud, Cut and As. According to another process, described in the Engineering and Mining Journal, 157, 5, 88 (1956), oxidic zinciferous material is leached with sulfuric acid to dissolve zinc and cadmium and the leach residue containing As, Sub, Bit Cud, Sun and Go is leached in hot, strong sulfuric acid. Go, As and Cud are precipitated ~Z38~
from the leach solution as sulfides which are roasted and leached once more. The final cake is subjected to distillation to convert Go to Joke which is further purified and hydrolyzed to Joy. A similar process is disclosed in U.S.
Patent 2 929 677, which issued March 22, 1960, and according to which oxidic zinciferous material is leached with sulfuric acid a ferris salt and sodium hydroxide solution are added to the leach solution to precipitate iron and germanium compounds, the precipitated compounds are ground with sodium chloride, digested with sulfuric acid concurrently volatilizing Joke, Juicy is precipitated from Joke solution and Juicy is ignited to Joy.
One of the major problems in processes for the recovery of germanium from oxidic zinciferous materials is the presence of metals such as copper, cadmium, arsenic and antimony, which, if not eliminated, will contaminate the germanium sulfide.
We have now found that this problem can be alleviated by leaching oxidic zinciferous material in two stages and carrying out the second stage in such a way that at least a portion of the Cut As and Sub are removed in the leach residue.
Germanium sulfide is then precipitated in a relatively pure form, arsenic being the major contaminant. More specifically, oxidic zinciferous material is subjected to a leach in sulfuric acid to dissolve germanium into a leach solution which is neutralized in the presence of ferris iron whereby a germanium - containing precipitate is formed. This precipitate also
2.
~3~9~:
contains Cut Cud, As and Sub. After washing out most of the cadmium, the precipitate is subjected to a second acid leach, or reteach, to dissolve the precipitate. Ferris iron is subsequently reduced to ferrous iron with lead or zinc sulfide concentrate and/or iron and a portion of the Cut As and Sub is eliminated. Preferably this reteach is carried out in three steps. In the first step, precipitate is dissolved, in the second step lead or zinc sulfide concentrate is added and in the third step, particulate iron is added. The final leach solution is separated and treated with hydrogen sulfide. The precipitate is recovered and further treated for the recovery of germanium.
It is an object of the present invention to provide a method for the recovery of germanium from germanium-containing material.
It is another object to provide an improved method for the recovery of a germanium concentrate from oxidic zinciferous material.
It is yet another object to provide a method for the recovery from oxidic zinciferous material of germanium sulfide with a reduced content of contaminating elements.
In accordance with these and-other objects of the present invention, to be described in detail hereinafter, there is provided a method for the recovery of germanium from germanium-containing oxidic material also containing arsenic, antimony, cadmium and copper, which method comprises the steps of leaching said material in sulfuric acid at atmospheric 12:3~19;2 pressure and autogenous temperature, maintaining the pi in the leach at a value in the range of about 1.0 to 2.5 and forming a leach solution and a leach residue; separating said leach solution from said leach residue; adding ferris iron to the solution to provide up to about lug ferris per lithe of solution, and adding a further amount of germanium-containing oxidic material to the separated leach solution in a neutral leach, said further amount being sufficient to raise the pi of the neutral leach solution to and to control the said pi at a 10 value in the range of about 3 to 5; separating neutral leach liquid from neutral leach solids and washing said solids;
treating the washed neutral leach solids with an excess amount of sulfuric acid forming a reaction slurry, said excess amount providing about 20 to 100 g H2SO4 per lithe of reaction slurry; adding to said reaction slurry in a reduction at least one reluctant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron to reduce ferris iron in and to cement a portion of the arsenic, antimony and copper from said reaction slurry, thereby forming a reduced reaction slurry;
separating said reduced reaction slurry in a liquid fraction and a solids fraction; providing in said liquid fraction sulfuric acid in a concentration of at least about 75 g/L;
adding to said liquid fraction a compound chosen from suitable soluble sulfides and hydrogen sulfide in an amount sufficient to precipitate germanium as germanium sulfide; and recovering said germanium sulfide in a germanium concentrate.
~2~81~3~
According to a preferred embodiment said reduction is carried out in a first step and a second step, said first step consisting of heating said reaction slurry to about 90C, adding a reluctant chosen from zinc sulfide concentrate and lead sulfide concentrate in an amount in excess with respect to the reaction with ferris sulfate and retaining the reaction slurry for about 15 to 30 minutes at about 90C; and said second step consisting of adding particulate iron in an amount at least sufficient to reduce residual ferris iron, and carrying out said second step at autogenous temperature for a time in the range of about 15 to 30 minutes.
Germanium-containing feed materials that can be processed in the method according to the invention are oxidic feed materials such as, for example, oxidic zinciferous feed material obtained as fumes and dusts in the processing of complex zinc/lead sulfide ores and concentrates. Beside zinc and lead, such ores and concentrates may also contain arsenic, antimony, bismuth, cadmium, copper, germanium, iron, precious metals, thallium tin, selenium, sulfate, chloride and fluoride.
The method of the invention and the manner in which it is carried out will become apparent from the following detailed description taken in conjunction with the accompanying drawing which is a flow sheet schematically illustrating an embodiment thereof.
With reference now to the drawing, oxidic feed is slurries with sulfuric acid, which may be in the form of return acid from cells for the electrowinning of zinc, and the slurry ~LZ3819;2 is fed to acid leach 1. Germanium is dissolved together with any zinc, arsenic, antimony, cadmium and copper. The leach is carried out at atmospheric pressure and at autogenous temperature which is usually in the range of about 30 to 50C.
The pi in the leach is maintained in the range of about 1.0 to 2.5, preferably about 2.0 to 2.5, which is equivalent to about 1 to 10, preferably 1 to 2 g/L, free acid, respectively. The retention time in the leach is in the range of about 30 to 60 minutes.
After completion of acid leach 1, the reaction slurry is subjected to liquid-solids separation 2. Generally, liquid-solids separations in the process are carried out by conventional means and may include settling, filtration, centrifuging and combinations thereof. Liquid-solids separation 2 preferably comprises thickening followed by filtration of the settled material. A suitable flocculent is preferably added to the settler. The solids fraction from separation 2 is discharged from the process as leach residue and the liquid fraction is fed as leach solution to neutral leach 3.
In neutral leach 3 a further amount of oxidic feed is added to the separated leach solution. The amount should be sufficient to raise the pi of the solution to a value in the range of about 3 to 5, preferably to a value of about 4. The pi is carefully controlled at about this value by regulating the amount of added feed. The amount of added oxidic feed is usually about 5 to 10% by weight of the total oxidic feed added 6.
~38~9Z
in the process. The reaction slurry in the neutral leach 3 must contain an amount of iron as ferris iron. This amount can be present initially but usually has to be added the usual oxidic feed does not contain iron). Addition of fork iron is done before the further amount of oxidic feed it added. The ferris iron can be added as a ferris iron salt or as a ferrous salt and a suitable oxidant such as, for example manganese dioxide, or anode mud from zinc electrowinning cells. The presence of ferris iron is necessary so that the dissolved germanium, as well as a portion of the copper, arsenic and antimony, can co-precipitate with the iron precipitating at a pi in the range of about 3 to 5 in the neutral leach. The presence of not more than about 1 g Fe per lithe of reaction slurry is desirable. Larger amounts would require additional oxidic feed to neutralize the acid released by the precipitation of the iron thereby increasing the volume of leach solids and reducing the grade of the germanium concentrate. The neutral leach is carried out at a temperature of about 40 to 50C and with a retention time in the range of about 30 to 60 minutes. The reaction slurry is discharged from neutral leach 3 and subjected to liquid-solids separation 4 to separate neutral leach liquid from neutral leach solids.
Liquid-solids separation 4 is preferably carried out by first settling the reaction slurry in a thickener in the presence of a suitable flocculent and subjecting the thickener under flow to filtration. rho neutral leach solids are carefully washed with water to remove a major portion of the 7.
~L23~92 cadmium in the solution. Any cadmium not removed will accompany the final germanium concentrate. The liquid fraction from separation is discharged from the process and the washed solids fraction is passed to reteach 5. The solids fraction contains precipitated iron as well as precipitated copper, arsenic, antimony and, of course, the germanium. Preferably, a portion of the solids fraction from separation 4, i.e. a portion of the thickener under flow, is recycled to neutral leach 4, as indicated with the interrupted line in the drawing. This recycling results in a reduction in the germanium content of the discharged liquid fraction, thus improving germanium recovery.
In reteach 5, the washed neutral leach solids are treated with sulfuric acid to dissolve the germanium. Arsenic, antimony and copper are also dissolved, as is the iron which dissolves as ferris iron. The reteach 5 is carried out under atmospheric pressure at autogenous temperature, the temperature usually being in the range of about 30 to 40C, and with a retention time in the range of about 15 to 30 minutes. The solids are mixed with sulfuric acid in excess sufficient to provide a pi of less than one. The amount of sulfuric acid is in the range of about 20 to 100, preferably about 30 to 75 g H2SO4 per lithe of reaction slurry. Below 30 g/L, increasing amounts of zinc would precipitate in a subsequent precipitation, and above 75 g/L H2SO4, the amount of added sulfate will adversely affect the sulfate balance in an integrated zinc plant operation.
aye In order to precipitate germanium in the leach solution as sulfide/ it is first necessary to reduce the ferris iron to the ferrous state. This is advantageously achieved in the reaction slurry of reteach 5 by a reduction with at least one reluctant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron, thereby forming a reduced reaction slurry. The reduction is preferably carried out as a two-step reduction using lead or zinc sulfide concentrate and iron as is shown in the accompanying drawing. In first reduction step 6, an amount of sulfide concentrate is added.
The sulfide concentrate reacts with ferris sulfate to give ferrous sulfate, zinc or lead sulfate and elemental sulfur.
Elemental sulfur and lead sulfate are readily removable in a subsequent liquid-solids separation. The amount of sulfide concentrate added is in excess with respect to the reaction with ferris sulfate. The reaction slurry is heated to about 90C, sulfide concentrate is added and the slurry is retained at about 90C, for about 15 to 30 minutes. The main advantage of using sulfide concentrate as a reluctant for ferris iron is that a portion of the arsenic, antimony and copper are cemented and can thereby be removed from the germanium-containing solution. The use of lead sulfide concentrate is preferred over that of zinc sulfide concentrate because of its superior reaction kinetics and its more favorable ability to cement arsenic, antimony and copper.
A further reduction of the arsenic, antimony and copper content and reduction of residual ferris iron is ISLES
attained in second reduction step 7 by adding to the reaction slurry a small amount of a particulate metal, preferably particulate iron, such as iron powder granules, nails, or shavings. The use of particulate iron with a large surface area, such as iron powder, is preferred The amount of particulate iron should be at least sufficient to reduce residual ferris iron and precipitate copper. If desired, an excess of iron may be added which further reduces the antimony and arsenic contents of the solution. The second reduction 7 is carried out at autogenous temperature and is usually completed in about 15 to 30 minutes or less. No Arizona evolution has been detected. By carrying out the reteach and the reductions in the presence of lead sulfide and iron, we have found that the copper content in the germanium-containing solution is considerably reduced and that the arsenic and antimony contents are somewhat reduced. As much as 99.8% of the copper content, up to 50% of the antimony content and up to 25% of the arsenic content are removed in the first and second reductions 6 and 7. After completion of the reactions, the reduced reaction slurry is discharged and subjected to liquid-solids separation 8. In liquid-solids separation 8, the solids are separated, washed with added wash water and removed from the process. The excess lead sulfide concentrate acts as a filter aid. The liquid fraction is passed Jo sulfide precipitation 9.
In sulfide precipitation 9, the liquid fraction is treated with a suitable soluble sulfide such as sodium sulfide 10 .
~23'~3~9Z
or sodium bisulfide or with hydrogen sulfide in an amount sufficient to precipitate germanium sulfide. In a preferred embodiment, the liquid fraction is first cooled to about 30C
or lower. Sulfuric acid is added to prevent the precipitation of iron, zinc and indium. The acid is preferably added as concentrated sulfuric acid to control solution bulk and in an amount providing at least about 75 g/L in the solution.
Hydrogen sulfide is gradually added and the redo potential is monitored during the addition. The redo potential at 10 completion of precipitation is about 100 my for a platinum versus saturated calmly electrode system. After precipitation 9 has been completed, any excess hydrogen sulfide is removed from the reaction slurry by stripping with air or nitrogen.
The reaction slurry is subsequently subjected to liquid-solids separation 10. The liquid fraction is removed from the process and the solids fraction is recovered as the final germanium concentrate.
A typical final concentrate contains about 10%
germanium, 30~ arsenic, 2% cadmium, 3% antimony and no copper.
The invention will now be illustrated by the following non-limitative examples.
Example 1 Oxidic zinciferous material (zinc oxide fume) containing, in percentages by weight, 0.09 Go, 50.95 Zen, 22.92 Pub, 0.578 As, 0.246 Sub, 1.04 Cud, 0.047 Cut and 0.23 In, was subjected to an acid leach. 27 kg material was slurries in a ~238~92 vessel with 166 L return acid from zinc electrowinning cells and reacted for 56 minutes. The temperature of the leach was 45 C and the pi was 2Ø The reaction slurry was discharged from the vessel and it was determined that the leach solution contained 135 Mel germanium and that 94.7% of the germanium had been extracted.
Exam 2 The leach of example 1 was repeated under similar conditions giving a reaction slurry. The leach solution was separated from the leach residue in a thickener. Perkily Eye (trade mark) was used as flocculent. To the 355 L of separated solution, containing 103 Mel Go, 150 Mel Sub, 110 Mel Cut 1700 Mel Cud and 65 Mel In, were added 1.1 g/L ferris iron and 2.3 kg zinc oxide fume slurries in 6.6L return acid to bring the pi up to a value of 4Ø The reaction slurry was agitated for 55 minutes. The temperature was 45 C. The slurry from the neutral leach was settled in a thickener. The 362L
separated neutral leach solution and 2.9 kg residue were analyzed. The analysis results are tabulated in Table I.
Table I
Compositions Go As Sub Cut Cud In Solution Mel 27 0.5 47 110 2000 4 Residue (%3 1.02.2 1.6 0.160.120.8 Distributions in -Solution 25 0.3 27 90 99 6 Residue 75 99.7 73 10 1 94 12.
~1~23~3~92 It can be seen from the tabulated results for this test that the germanium has been concentrated to I that almost all arsenic and indium and a major portion of the antimony report in the concentrate while copper and cadmium have been mostly eliminated.
Example 3 The test of example 2 was repeated. Leach solution from the acid leach was separated from leach residue in a thickener using flocculent. Separated solution contained 185 10 Mel germanium. Zinc oxide fume slurries in return acid as well as 0.8 g/L ferris iron were added to the separated solution in the neutral leach. The pi in the neutral leach was 4.1. Slurry from the neutral leach was settled in a thickener and portion of the thickener under flow was recycled to the neutral leach. The volume of recycled material was one fifth of the volume of material fed to the neutral leach.
The thickener overflow analyzed 42 Mel germanium before and 26 Mel germanium after the recycling of a portion of the under flow.
The results shows that recycling a portion of the neutral leach solids to the neutral leach improves the recovery of germanium.
13.
~.~38~L92 Exhume 4 The washed solids from two neutral leaches were separately relished in sulfuric acid. No reluctant was added. Different acid concentrations and pulp densities were used. It was shown that the lower acid concentration and lower pulp density give extraction of germanium of about 90%, which extraction decreases with higher pulp density. The results are given in Table II.
Table II
Final Free Volume Germanium Test H2SO4 or Weight Dust.
No. Material in Lo Weight Analysis in in %
1 Feed Solids 132 g 0.62~0.82 100 Residue 80 g 0.10~ 0.08 9 Solution 43 970 my 0.87 g/L 0.84 91 2 Feed Solids 265 g 0.62%1.60 100 Residue 165 g 0.31% 0.5132 Solution 103720 my 1.50 g/L 1.10 68 Example 5 The reteach was repeated in the presence of iron grit (100% - 50 mesh, 40% - 120 mesh, 30% - 200 mesh US Sieve Series) in an amount which was 1.4 times the amount required to reduce the ferris iron. The reduction was carried out at 70C and was essentially complete in 30 minutes. Solution was analyzed before and after the addition of iron. Results are shown in Table III.
14.
Table III
Leach Solution Analysis in Mel Go Fe Sub As Cut Cud before iron addition 2200 61000 760 7000 1500 500 after iron addition 2000 83000 130 1600 5 370 Some dilution with water occurred during the test.
The results show that a reteach in the presence of particulate iron results in a large reduction in the arsenic, antimony and copper and cadmium in the leach solution.
Example 6 The reteach was repeated with the addition of lead sulfide concentrate as reluctant. The slurry was heated to 90C and the leach and reduction continued for 30 minutes.
Solution was analyzed before and after the addition of the 10 reluctant. The results are shown in Table IV.
Table IV
Leach Solution Analysis in Mel Go Fe Sub As Cut Cud before Pus addition 1800 34000 580 4000 830 425 after Pus addition 1800 38000 74 2000 26 470 The results show that reduction with lead sulfide concentrate also results in a reduction of the As, Sub and Cut contents of the germanium containing solution.
Example 7 The reteach was conducted, and was followed by a first reduction with load sulfide concentrate and a second reduction
~3~9~:
contains Cut Cud, As and Sub. After washing out most of the cadmium, the precipitate is subjected to a second acid leach, or reteach, to dissolve the precipitate. Ferris iron is subsequently reduced to ferrous iron with lead or zinc sulfide concentrate and/or iron and a portion of the Cut As and Sub is eliminated. Preferably this reteach is carried out in three steps. In the first step, precipitate is dissolved, in the second step lead or zinc sulfide concentrate is added and in the third step, particulate iron is added. The final leach solution is separated and treated with hydrogen sulfide. The precipitate is recovered and further treated for the recovery of germanium.
It is an object of the present invention to provide a method for the recovery of germanium from germanium-containing material.
It is another object to provide an improved method for the recovery of a germanium concentrate from oxidic zinciferous material.
It is yet another object to provide a method for the recovery from oxidic zinciferous material of germanium sulfide with a reduced content of contaminating elements.
In accordance with these and-other objects of the present invention, to be described in detail hereinafter, there is provided a method for the recovery of germanium from germanium-containing oxidic material also containing arsenic, antimony, cadmium and copper, which method comprises the steps of leaching said material in sulfuric acid at atmospheric 12:3~19;2 pressure and autogenous temperature, maintaining the pi in the leach at a value in the range of about 1.0 to 2.5 and forming a leach solution and a leach residue; separating said leach solution from said leach residue; adding ferris iron to the solution to provide up to about lug ferris per lithe of solution, and adding a further amount of germanium-containing oxidic material to the separated leach solution in a neutral leach, said further amount being sufficient to raise the pi of the neutral leach solution to and to control the said pi at a 10 value in the range of about 3 to 5; separating neutral leach liquid from neutral leach solids and washing said solids;
treating the washed neutral leach solids with an excess amount of sulfuric acid forming a reaction slurry, said excess amount providing about 20 to 100 g H2SO4 per lithe of reaction slurry; adding to said reaction slurry in a reduction at least one reluctant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron to reduce ferris iron in and to cement a portion of the arsenic, antimony and copper from said reaction slurry, thereby forming a reduced reaction slurry;
separating said reduced reaction slurry in a liquid fraction and a solids fraction; providing in said liquid fraction sulfuric acid in a concentration of at least about 75 g/L;
adding to said liquid fraction a compound chosen from suitable soluble sulfides and hydrogen sulfide in an amount sufficient to precipitate germanium as germanium sulfide; and recovering said germanium sulfide in a germanium concentrate.
~2~81~3~
According to a preferred embodiment said reduction is carried out in a first step and a second step, said first step consisting of heating said reaction slurry to about 90C, adding a reluctant chosen from zinc sulfide concentrate and lead sulfide concentrate in an amount in excess with respect to the reaction with ferris sulfate and retaining the reaction slurry for about 15 to 30 minutes at about 90C; and said second step consisting of adding particulate iron in an amount at least sufficient to reduce residual ferris iron, and carrying out said second step at autogenous temperature for a time in the range of about 15 to 30 minutes.
Germanium-containing feed materials that can be processed in the method according to the invention are oxidic feed materials such as, for example, oxidic zinciferous feed material obtained as fumes and dusts in the processing of complex zinc/lead sulfide ores and concentrates. Beside zinc and lead, such ores and concentrates may also contain arsenic, antimony, bismuth, cadmium, copper, germanium, iron, precious metals, thallium tin, selenium, sulfate, chloride and fluoride.
The method of the invention and the manner in which it is carried out will become apparent from the following detailed description taken in conjunction with the accompanying drawing which is a flow sheet schematically illustrating an embodiment thereof.
With reference now to the drawing, oxidic feed is slurries with sulfuric acid, which may be in the form of return acid from cells for the electrowinning of zinc, and the slurry ~LZ3819;2 is fed to acid leach 1. Germanium is dissolved together with any zinc, arsenic, antimony, cadmium and copper. The leach is carried out at atmospheric pressure and at autogenous temperature which is usually in the range of about 30 to 50C.
The pi in the leach is maintained in the range of about 1.0 to 2.5, preferably about 2.0 to 2.5, which is equivalent to about 1 to 10, preferably 1 to 2 g/L, free acid, respectively. The retention time in the leach is in the range of about 30 to 60 minutes.
After completion of acid leach 1, the reaction slurry is subjected to liquid-solids separation 2. Generally, liquid-solids separations in the process are carried out by conventional means and may include settling, filtration, centrifuging and combinations thereof. Liquid-solids separation 2 preferably comprises thickening followed by filtration of the settled material. A suitable flocculent is preferably added to the settler. The solids fraction from separation 2 is discharged from the process as leach residue and the liquid fraction is fed as leach solution to neutral leach 3.
In neutral leach 3 a further amount of oxidic feed is added to the separated leach solution. The amount should be sufficient to raise the pi of the solution to a value in the range of about 3 to 5, preferably to a value of about 4. The pi is carefully controlled at about this value by regulating the amount of added feed. The amount of added oxidic feed is usually about 5 to 10% by weight of the total oxidic feed added 6.
~38~9Z
in the process. The reaction slurry in the neutral leach 3 must contain an amount of iron as ferris iron. This amount can be present initially but usually has to be added the usual oxidic feed does not contain iron). Addition of fork iron is done before the further amount of oxidic feed it added. The ferris iron can be added as a ferris iron salt or as a ferrous salt and a suitable oxidant such as, for example manganese dioxide, or anode mud from zinc electrowinning cells. The presence of ferris iron is necessary so that the dissolved germanium, as well as a portion of the copper, arsenic and antimony, can co-precipitate with the iron precipitating at a pi in the range of about 3 to 5 in the neutral leach. The presence of not more than about 1 g Fe per lithe of reaction slurry is desirable. Larger amounts would require additional oxidic feed to neutralize the acid released by the precipitation of the iron thereby increasing the volume of leach solids and reducing the grade of the germanium concentrate. The neutral leach is carried out at a temperature of about 40 to 50C and with a retention time in the range of about 30 to 60 minutes. The reaction slurry is discharged from neutral leach 3 and subjected to liquid-solids separation 4 to separate neutral leach liquid from neutral leach solids.
Liquid-solids separation 4 is preferably carried out by first settling the reaction slurry in a thickener in the presence of a suitable flocculent and subjecting the thickener under flow to filtration. rho neutral leach solids are carefully washed with water to remove a major portion of the 7.
~L23~92 cadmium in the solution. Any cadmium not removed will accompany the final germanium concentrate. The liquid fraction from separation is discharged from the process and the washed solids fraction is passed to reteach 5. The solids fraction contains precipitated iron as well as precipitated copper, arsenic, antimony and, of course, the germanium. Preferably, a portion of the solids fraction from separation 4, i.e. a portion of the thickener under flow, is recycled to neutral leach 4, as indicated with the interrupted line in the drawing. This recycling results in a reduction in the germanium content of the discharged liquid fraction, thus improving germanium recovery.
In reteach 5, the washed neutral leach solids are treated with sulfuric acid to dissolve the germanium. Arsenic, antimony and copper are also dissolved, as is the iron which dissolves as ferris iron. The reteach 5 is carried out under atmospheric pressure at autogenous temperature, the temperature usually being in the range of about 30 to 40C, and with a retention time in the range of about 15 to 30 minutes. The solids are mixed with sulfuric acid in excess sufficient to provide a pi of less than one. The amount of sulfuric acid is in the range of about 20 to 100, preferably about 30 to 75 g H2SO4 per lithe of reaction slurry. Below 30 g/L, increasing amounts of zinc would precipitate in a subsequent precipitation, and above 75 g/L H2SO4, the amount of added sulfate will adversely affect the sulfate balance in an integrated zinc plant operation.
aye In order to precipitate germanium in the leach solution as sulfide/ it is first necessary to reduce the ferris iron to the ferrous state. This is advantageously achieved in the reaction slurry of reteach 5 by a reduction with at least one reluctant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron, thereby forming a reduced reaction slurry. The reduction is preferably carried out as a two-step reduction using lead or zinc sulfide concentrate and iron as is shown in the accompanying drawing. In first reduction step 6, an amount of sulfide concentrate is added.
The sulfide concentrate reacts with ferris sulfate to give ferrous sulfate, zinc or lead sulfate and elemental sulfur.
Elemental sulfur and lead sulfate are readily removable in a subsequent liquid-solids separation. The amount of sulfide concentrate added is in excess with respect to the reaction with ferris sulfate. The reaction slurry is heated to about 90C, sulfide concentrate is added and the slurry is retained at about 90C, for about 15 to 30 minutes. The main advantage of using sulfide concentrate as a reluctant for ferris iron is that a portion of the arsenic, antimony and copper are cemented and can thereby be removed from the germanium-containing solution. The use of lead sulfide concentrate is preferred over that of zinc sulfide concentrate because of its superior reaction kinetics and its more favorable ability to cement arsenic, antimony and copper.
A further reduction of the arsenic, antimony and copper content and reduction of residual ferris iron is ISLES
attained in second reduction step 7 by adding to the reaction slurry a small amount of a particulate metal, preferably particulate iron, such as iron powder granules, nails, or shavings. The use of particulate iron with a large surface area, such as iron powder, is preferred The amount of particulate iron should be at least sufficient to reduce residual ferris iron and precipitate copper. If desired, an excess of iron may be added which further reduces the antimony and arsenic contents of the solution. The second reduction 7 is carried out at autogenous temperature and is usually completed in about 15 to 30 minutes or less. No Arizona evolution has been detected. By carrying out the reteach and the reductions in the presence of lead sulfide and iron, we have found that the copper content in the germanium-containing solution is considerably reduced and that the arsenic and antimony contents are somewhat reduced. As much as 99.8% of the copper content, up to 50% of the antimony content and up to 25% of the arsenic content are removed in the first and second reductions 6 and 7. After completion of the reactions, the reduced reaction slurry is discharged and subjected to liquid-solids separation 8. In liquid-solids separation 8, the solids are separated, washed with added wash water and removed from the process. The excess lead sulfide concentrate acts as a filter aid. The liquid fraction is passed Jo sulfide precipitation 9.
In sulfide precipitation 9, the liquid fraction is treated with a suitable soluble sulfide such as sodium sulfide 10 .
~23'~3~9Z
or sodium bisulfide or with hydrogen sulfide in an amount sufficient to precipitate germanium sulfide. In a preferred embodiment, the liquid fraction is first cooled to about 30C
or lower. Sulfuric acid is added to prevent the precipitation of iron, zinc and indium. The acid is preferably added as concentrated sulfuric acid to control solution bulk and in an amount providing at least about 75 g/L in the solution.
Hydrogen sulfide is gradually added and the redo potential is monitored during the addition. The redo potential at 10 completion of precipitation is about 100 my for a platinum versus saturated calmly electrode system. After precipitation 9 has been completed, any excess hydrogen sulfide is removed from the reaction slurry by stripping with air or nitrogen.
The reaction slurry is subsequently subjected to liquid-solids separation 10. The liquid fraction is removed from the process and the solids fraction is recovered as the final germanium concentrate.
A typical final concentrate contains about 10%
germanium, 30~ arsenic, 2% cadmium, 3% antimony and no copper.
The invention will now be illustrated by the following non-limitative examples.
Example 1 Oxidic zinciferous material (zinc oxide fume) containing, in percentages by weight, 0.09 Go, 50.95 Zen, 22.92 Pub, 0.578 As, 0.246 Sub, 1.04 Cud, 0.047 Cut and 0.23 In, was subjected to an acid leach. 27 kg material was slurries in a ~238~92 vessel with 166 L return acid from zinc electrowinning cells and reacted for 56 minutes. The temperature of the leach was 45 C and the pi was 2Ø The reaction slurry was discharged from the vessel and it was determined that the leach solution contained 135 Mel germanium and that 94.7% of the germanium had been extracted.
Exam 2 The leach of example 1 was repeated under similar conditions giving a reaction slurry. The leach solution was separated from the leach residue in a thickener. Perkily Eye (trade mark) was used as flocculent. To the 355 L of separated solution, containing 103 Mel Go, 150 Mel Sub, 110 Mel Cut 1700 Mel Cud and 65 Mel In, were added 1.1 g/L ferris iron and 2.3 kg zinc oxide fume slurries in 6.6L return acid to bring the pi up to a value of 4Ø The reaction slurry was agitated for 55 minutes. The temperature was 45 C. The slurry from the neutral leach was settled in a thickener. The 362L
separated neutral leach solution and 2.9 kg residue were analyzed. The analysis results are tabulated in Table I.
Table I
Compositions Go As Sub Cut Cud In Solution Mel 27 0.5 47 110 2000 4 Residue (%3 1.02.2 1.6 0.160.120.8 Distributions in -Solution 25 0.3 27 90 99 6 Residue 75 99.7 73 10 1 94 12.
~1~23~3~92 It can be seen from the tabulated results for this test that the germanium has been concentrated to I that almost all arsenic and indium and a major portion of the antimony report in the concentrate while copper and cadmium have been mostly eliminated.
Example 3 The test of example 2 was repeated. Leach solution from the acid leach was separated from leach residue in a thickener using flocculent. Separated solution contained 185 10 Mel germanium. Zinc oxide fume slurries in return acid as well as 0.8 g/L ferris iron were added to the separated solution in the neutral leach. The pi in the neutral leach was 4.1. Slurry from the neutral leach was settled in a thickener and portion of the thickener under flow was recycled to the neutral leach. The volume of recycled material was one fifth of the volume of material fed to the neutral leach.
The thickener overflow analyzed 42 Mel germanium before and 26 Mel germanium after the recycling of a portion of the under flow.
The results shows that recycling a portion of the neutral leach solids to the neutral leach improves the recovery of germanium.
13.
~.~38~L92 Exhume 4 The washed solids from two neutral leaches were separately relished in sulfuric acid. No reluctant was added. Different acid concentrations and pulp densities were used. It was shown that the lower acid concentration and lower pulp density give extraction of germanium of about 90%, which extraction decreases with higher pulp density. The results are given in Table II.
Table II
Final Free Volume Germanium Test H2SO4 or Weight Dust.
No. Material in Lo Weight Analysis in in %
1 Feed Solids 132 g 0.62~0.82 100 Residue 80 g 0.10~ 0.08 9 Solution 43 970 my 0.87 g/L 0.84 91 2 Feed Solids 265 g 0.62%1.60 100 Residue 165 g 0.31% 0.5132 Solution 103720 my 1.50 g/L 1.10 68 Example 5 The reteach was repeated in the presence of iron grit (100% - 50 mesh, 40% - 120 mesh, 30% - 200 mesh US Sieve Series) in an amount which was 1.4 times the amount required to reduce the ferris iron. The reduction was carried out at 70C and was essentially complete in 30 minutes. Solution was analyzed before and after the addition of iron. Results are shown in Table III.
14.
Table III
Leach Solution Analysis in Mel Go Fe Sub As Cut Cud before iron addition 2200 61000 760 7000 1500 500 after iron addition 2000 83000 130 1600 5 370 Some dilution with water occurred during the test.
The results show that a reteach in the presence of particulate iron results in a large reduction in the arsenic, antimony and copper and cadmium in the leach solution.
Example 6 The reteach was repeated with the addition of lead sulfide concentrate as reluctant. The slurry was heated to 90C and the leach and reduction continued for 30 minutes.
Solution was analyzed before and after the addition of the 10 reluctant. The results are shown in Table IV.
Table IV
Leach Solution Analysis in Mel Go Fe Sub As Cut Cud before Pus addition 1800 34000 580 4000 830 425 after Pus addition 1800 38000 74 2000 26 470 The results show that reduction with lead sulfide concentrate also results in a reduction of the As, Sub and Cut contents of the germanium containing solution.
Example 7 The reteach was conducted, and was followed by a first reduction with load sulfide concentrate and a second reduction
3 I
with a small amount of iron grit. 412 g of moist solids containing 263 ml moisture and 0.63~ Go from the neutral leach were relished with 2050 my of diluted return acid at 90C
for 30 minutes. 300 g of lead sulfide concentrate were added and after 30 minutes 3g of iron grit were added. 15 minutes after the iron addition the slurry was subjected lo liquid-solids separation and the solids and liquid fractions were analyzed for germanium. The 2360 my solution contained 1.1 g/L germanium and the 556 g solids contained 0.06%
germanium. The germanium extraction was calculated to be 87%.
The final solution was also found to contain 25 Mel Fez , 22600 Mel total iron, 1750 Mel As, 290 Mel Sub, 1 Mel Cut and 440 Mel Cud.
As can be seen from the results, ferris iron was substantially reduced to the ferrous state and copper was virtually eliminated.
Example 8 The test of Example 7 was repeated. Neutral leach residue, 4.0 kg dry weight and containing 0.9~ Go, 2.3% As and 8.5% Fe, was relished, reduced with 2.9 kg lead sulfide concentrate and subsequently further reduced with 63g iron powder i.e. about twenty times the amount required to reduce ferris. Solution was analyzed before and after lead sulfide reduction and following reduction with iron. Results are given in Table V.
16.
ISLE
Table V
Go As Fe Sub Cut Cud Lo Mel my Solution before Sulfide Reduction 1.5 3.7 14 800 390 225 Solution after Sulfide Reduction 1.4 3.4 - ~05 470 230 Solution after 19.3 Foe Iron Reduction 1.4 2.8 0.02 Fez+ 375 1.2 220 It can be seen from the results that ferris iron is substantially reduced to the ferrous state, that copper is essentially eliminated and that the contents of arsenic and antimony have been reduced.
Example 9 The solutions obtained from the test described in Example 5, 6 and 7 were treated with hydrogen sulfide. Prior to the addition of hydrogen sulfide, the solutions were cooled to room temperature and brought up to 95 g/L sulfuric acid.
Hydrogen sulfide was sparred into each of the solutions at a rate of 100 my H2S/minute and the redo potential was monitored during the addition of hydrogen sulfide until the end point was indicated at about 100 my at which point the addition of hydrogen sulfide was stopped. The probe contained a platinum electrode and a saturated calmly electrode.
For each of the precipitation tests, the germanium and arsenic contents were determined. Results are given in Table VI.
lZ3~3~9~
Table VI
Solution from Example Composition Weight Distribution in I or % in g in %
Quantity Go Age As Go As Head 1.5 L 1.7 1.2 2.6 1.9 100100 Precipitate 10.2 g 24~1 18.1 2.4~ 1.9 95100 Solution 105 L 0.09 0.001 0.14 0.002 75 0 Solution from Example 6 Head 105 L 1.6 1.8 2.4 2.7 100100 Precipitate 10.3 g 23.0 24.1 2.37 2.5 99100 Solution 1.5 L 0.02 0.00 0.03 - 1 0 Solution from Example 7 Head 1.34 L 0.76 1.4 1.02 1.9 100100 Precipitate 4.75 g 20.4 19.7 0.97 0.94 95 56 Solution 1.34 L 0.037 0.55 0.05 0.74 5 44 It can be seen from the results given in Table VI that the highest germanium concentrate grade was obtained with solution reduced with iron only, especially because of the lower arsenic level. The concentrate grade obtained from solution reduced with only lead concentrate only was lower because of the increased level of impurities. It can also be seen that the arsenic precipitates with the germanium and forms the major contaminant It is understood that variations and modifications can be made in the process according to the invention without departing from the spirit and scope of the invention as defined by the claims.
18.
with a small amount of iron grit. 412 g of moist solids containing 263 ml moisture and 0.63~ Go from the neutral leach were relished with 2050 my of diluted return acid at 90C
for 30 minutes. 300 g of lead sulfide concentrate were added and after 30 minutes 3g of iron grit were added. 15 minutes after the iron addition the slurry was subjected lo liquid-solids separation and the solids and liquid fractions were analyzed for germanium. The 2360 my solution contained 1.1 g/L germanium and the 556 g solids contained 0.06%
germanium. The germanium extraction was calculated to be 87%.
The final solution was also found to contain 25 Mel Fez , 22600 Mel total iron, 1750 Mel As, 290 Mel Sub, 1 Mel Cut and 440 Mel Cud.
As can be seen from the results, ferris iron was substantially reduced to the ferrous state and copper was virtually eliminated.
Example 8 The test of Example 7 was repeated. Neutral leach residue, 4.0 kg dry weight and containing 0.9~ Go, 2.3% As and 8.5% Fe, was relished, reduced with 2.9 kg lead sulfide concentrate and subsequently further reduced with 63g iron powder i.e. about twenty times the amount required to reduce ferris. Solution was analyzed before and after lead sulfide reduction and following reduction with iron. Results are given in Table V.
16.
ISLE
Table V
Go As Fe Sub Cut Cud Lo Mel my Solution before Sulfide Reduction 1.5 3.7 14 800 390 225 Solution after Sulfide Reduction 1.4 3.4 - ~05 470 230 Solution after 19.3 Foe Iron Reduction 1.4 2.8 0.02 Fez+ 375 1.2 220 It can be seen from the results that ferris iron is substantially reduced to the ferrous state, that copper is essentially eliminated and that the contents of arsenic and antimony have been reduced.
Example 9 The solutions obtained from the test described in Example 5, 6 and 7 were treated with hydrogen sulfide. Prior to the addition of hydrogen sulfide, the solutions were cooled to room temperature and brought up to 95 g/L sulfuric acid.
Hydrogen sulfide was sparred into each of the solutions at a rate of 100 my H2S/minute and the redo potential was monitored during the addition of hydrogen sulfide until the end point was indicated at about 100 my at which point the addition of hydrogen sulfide was stopped. The probe contained a platinum electrode and a saturated calmly electrode.
For each of the precipitation tests, the germanium and arsenic contents were determined. Results are given in Table VI.
lZ3~3~9~
Table VI
Solution from Example Composition Weight Distribution in I or % in g in %
Quantity Go Age As Go As Head 1.5 L 1.7 1.2 2.6 1.9 100100 Precipitate 10.2 g 24~1 18.1 2.4~ 1.9 95100 Solution 105 L 0.09 0.001 0.14 0.002 75 0 Solution from Example 6 Head 105 L 1.6 1.8 2.4 2.7 100100 Precipitate 10.3 g 23.0 24.1 2.37 2.5 99100 Solution 1.5 L 0.02 0.00 0.03 - 1 0 Solution from Example 7 Head 1.34 L 0.76 1.4 1.02 1.9 100100 Precipitate 4.75 g 20.4 19.7 0.97 0.94 95 56 Solution 1.34 L 0.037 0.55 0.05 0.74 5 44 It can be seen from the results given in Table VI that the highest germanium concentrate grade was obtained with solution reduced with iron only, especially because of the lower arsenic level. The concentrate grade obtained from solution reduced with only lead concentrate only was lower because of the increased level of impurities. It can also be seen that the arsenic precipitates with the germanium and forms the major contaminant It is understood that variations and modifications can be made in the process according to the invention without departing from the spirit and scope of the invention as defined by the claims.
18.
Claims (12)
1. A method for the recovery of germanium from germanium-containing oxidic material also containing arsenic, antimony, cadmium and copper, which method comprises the steps of leaching said material in sulfuric acid at atmospheric pressure and autogenous temperature, maintaining the pH in the leach at a value in the range of about 1.0 to 2.5 and forming a leach solution and a leach residue; separating said leach solution from said leach residue; adding ferric iron to the solution to provide up to about 1 g ferric per litre of solution, and adding a further amount of germanium-containing oxidic material to the separated leach solution in a neutral leach, said further amount being sufficient to raise the pH of the neutral leach solution to and to control the said pH at a value in the range of about 3 to 5; separating neutral leach liquid from neutral leach solids and washing said solids;
treating the washed neutral leach solids with an excess amount of sulfuric acid forming a reaction slurry, said excess amount providing about 20 to 100 g H2SO4 per litre of reaction slurry; adding to said reaction slurry in a reduction at least one reductant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron to reduce ferric iron in and to cement a portion of the arsenic, antimony and copper from said reaction slurry, thereby forming a reduced reaction slurry;
separating said reduced reaction slurry in a liquid fraction and a solids fraction; providing in said liquid fraction at least 75 g/L sulfuric acid; adding to said liquid fraction a suitable compound chosen from soluble sulfides and hydrogen sulfide in an amount sufficient to precipitate germanium as germanium sulfide; and recovering said germanium sulfide in a germanium concentrate.
treating the washed neutral leach solids with an excess amount of sulfuric acid forming a reaction slurry, said excess amount providing about 20 to 100 g H2SO4 per litre of reaction slurry; adding to said reaction slurry in a reduction at least one reductant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron to reduce ferric iron in and to cement a portion of the arsenic, antimony and copper from said reaction slurry, thereby forming a reduced reaction slurry;
separating said reduced reaction slurry in a liquid fraction and a solids fraction; providing in said liquid fraction at least 75 g/L sulfuric acid; adding to said liquid fraction a suitable compound chosen from soluble sulfides and hydrogen sulfide in an amount sufficient to precipitate germanium as germanium sulfide; and recovering said germanium sulfide in a germanium concentrate.
2. A method as claimed in claim 1, wherein said reduction is carried out in a first step and a second step, said first step consisting of heating said reaction slurry to a temperature of about 90°C, adding a reductant chosen from zinc sulfide concentrate and lead sulfide concentrate in an amount in excess with respect to the reaction with ferric sulfate and retaining the reaction slurry for about 15 to 30 minutes at about 90°C; and said second step consisting of adding particulate iron in an amount at least sufficient to reduce residual ferric iron, and carrying out said second step at autogenous temperature for a time in the range of about 15 to 30 minutes.
3. A method as claimed in claim 1 or 2, wherein a portion of the separated neutral leach solids is recycled to the neutral leach.
4. A method as claimed in claim 1 or 2, wherein the reductants are lead sulfide concentrate and iron.
5. A method and claimed in claim 1 or 2, wherein the reductants are zinc sulfide concentrate and iron.
6. A method as claimed in claim 1 or 2, wherein the pH in the leach is maintained at a value in the range of about 2.0 to 2.5; the pH in the neutral leach is controlled at a value of about 4; the excess amount of sulfuric acid provides about 30 to 75 g H2SO4 per litre of reaction slurry; a portion of the separated neutral leach solids is recycled to the neutral leach; and the reductants are lead sulfide concentrate and iron.
7. A method as claimed in claim 2, wherein the amount of particulate iron added is in excess of the amount required to reduce residual ferric iron and to precipitate copper.
8. A method as claimed in claim 1 or 2, wherein said ferric iron is added to the solution in the neutral leach prior to the addition of a further amount of oxidic material, said ferric iron being added as a ferric iron salt or as a ferrous salt and an oxidant selected from manganese dioxide and anode mud from zinc electrowinning cells.
9. In a method for the recovery of germanium from oxidic zinciferous material comprising germanium, arsenic, antimony and copper, said method including leaching said material with sulfuric acid, neutralizing leach solution to form a germanium-containing precipitate in the presence of ferric iron, redissolving said precipitate into a solution and precipitating germanium from said solution as germanium sulfide, the improvement which comprises adding at least one reductant chosen from zinc sulfide concentrate, lead sulfide concentrate and iron to said solution prior to precipitating germanium therefrom, whereby ferric iron is reduced to the ferrous state and at least a portion of the arsenic, antimony and copper dissolved in said solution is removed from said solution.
10. The improvement as claimed in claim 9, wherein reluctant is added in two steps consisting of heating said solution in the first step to a temperature of about 90°C, adding a material chosen from zinc sulfide concentrate and lead sulfide concentrate in an amount in excess of the amount necessary to reduce at least a portion of the ferris iron and adding particulate iron in the second step about 15 to 30 minutes after the addition of the sulfide concentrate and in an amount at least sufficient to reduce the remaining portion of the ferris iron.
11. The improvement as claimed in claim 10, wherein said reluctant is lead sulfide concentrate.
12. The improvement as claimed in claim 10, wherein the amount of particulate iron is added in excess of the amount required to reduce residual iron and to precipitate copper.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000470878A CA1238192A (en) | 1984-12-21 | 1984-12-21 | Method for the recovery of germanium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000470878A CA1238192A (en) | 1984-12-21 | 1984-12-21 | Method for the recovery of germanium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1238192A true CA1238192A (en) | 1988-06-21 |
Family
ID=4129439
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000470878A Expired CA1238192A (en) | 1984-12-21 | 1984-12-21 | Method for the recovery of germanium |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1238192A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002099145A1 (en) * | 2001-06-07 | 2002-12-12 | Elcogas, S.A. | Method for recovering metals from the flying ashes generated in an integrated gasification combined cycle-type (igcc) thermal station |
| CN102766765A (en) * | 2012-08-07 | 2012-11-07 | 四川四环电锌有限公司 | Zinc oxide powder recycling method |
| CN104046801A (en) * | 2014-06-18 | 2014-09-17 | 贵州顶效开发区宏达金属综合回收有限公司 | Method for extracting germanium from germanium-silicon raw materials |
| CN106381402A (en) * | 2016-08-31 | 2017-02-08 | 四川省新源泰环保科技有限责任公司 | Method for recovering germanium and copper from germanium-copper ore |
| CN106801151A (en) * | 2017-01-22 | 2017-06-06 | 中国恩菲工程技术有限公司 | The method of flyash reduction melting enriched germanium |
| CN113621836A (en) * | 2021-08-13 | 2021-11-09 | 衢州华友钴新材料有限公司 | Method for selectively precipitating germanium from acidic solution containing cobalt, nickel, germanium and iron |
| CN113652558A (en) * | 2021-07-30 | 2021-11-16 | 葫芦岛锌业股份有限公司 | Method for recovering germanium from germanium-containing waste liquid |
| CN115261644A (en) * | 2022-08-16 | 2022-11-01 | 广东先导稀材股份有限公司 | Method for purifying germanium-containing material |
| CN115874058A (en) * | 2023-03-02 | 2023-03-31 | 昆明理工大学 | Method for efficiently enriching germanium by pre-dezincification and neutralization of zinc oxide smoke dust containing germanium |
-
1984
- 1984-12-21 CA CA000470878A patent/CA1238192A/en not_active Expired
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002099145A1 (en) * | 2001-06-07 | 2002-12-12 | Elcogas, S.A. | Method for recovering metals from the flying ashes generated in an integrated gasification combined cycle-type (igcc) thermal station |
| ES2178612A1 (en) * | 2001-06-07 | 2002-12-16 | Elcogas S A | Method for recovering germanium and other metals from fly ash generated in an integrated gasification combined cycle-type (igcc) thermal station |
| CN102766765A (en) * | 2012-08-07 | 2012-11-07 | 四川四环电锌有限公司 | Zinc oxide powder recycling method |
| CN104046801A (en) * | 2014-06-18 | 2014-09-17 | 贵州顶效开发区宏达金属综合回收有限公司 | Method for extracting germanium from germanium-silicon raw materials |
| CN106381402A (en) * | 2016-08-31 | 2017-02-08 | 四川省新源泰环保科技有限责任公司 | Method for recovering germanium and copper from germanium-copper ore |
| CN106801151A (en) * | 2017-01-22 | 2017-06-06 | 中国恩菲工程技术有限公司 | The method of flyash reduction melting enriched germanium |
| CN113652558A (en) * | 2021-07-30 | 2021-11-16 | 葫芦岛锌业股份有限公司 | Method for recovering germanium from germanium-containing waste liquid |
| CN113621836A (en) * | 2021-08-13 | 2021-11-09 | 衢州华友钴新材料有限公司 | Method for selectively precipitating germanium from acidic solution containing cobalt, nickel, germanium and iron |
| CN115261644A (en) * | 2022-08-16 | 2022-11-01 | 广东先导稀材股份有限公司 | Method for purifying germanium-containing material |
| CN115874058A (en) * | 2023-03-02 | 2023-03-31 | 昆明理工大学 | Method for efficiently enriching germanium by pre-dezincification and neutralization of zinc oxide smoke dust containing germanium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0100237B1 (en) | Recovery of zinc from zinc-containing sulphidic material | |
| US3976743A (en) | Treatment of zinc plant residue | |
| US4440569A (en) | Recovery of zinc from zinc-containing sulphidic material | |
| CA2160488C (en) | Recovery of metals from sulphidic material | |
| US4676828A (en) | Process for the leaching of sulphides containing zinc and iron | |
| CA1116869A (en) | Recovery of copper from arsenic-containing metallurgical waste materials | |
| US4545963A (en) | Process for separately recovering zinc and lead values from zinc and lead containing sulphidic ore | |
| KR20050089867A (en) | Recovering metals from sulfidic materials | |
| Harvey | The hydrometallurgical extraction of zinc by ammonium carbonate: a review of the Schnabel process | |
| DE60220705T2 (en) | METHOD FOR PROCESSING COPPER-CONTAINING MOLYBDEN CONCENTRATE | |
| EP0096499B1 (en) | Recovery of zinc from zinc-containing sulphidic material | |
| US4505744A (en) | Recovery of zinc from zinc containing sulphidic material | |
| CA1238192A (en) | Method for the recovery of germanium | |
| JP3052535B2 (en) | Treatment of smelting intermediates | |
| CA2825228C (en) | Precipitation of zinc from solution | |
| JPS62211B2 (en) | ||
| JPH04311541A (en) | Wet-type treating method for zinc concentration and zinc leaching residue at the same time | |
| RU2353679C2 (en) | Metals extraction from sulfide materials | |
| GB2114966A (en) | Recovery of zinc from sulphidic material | |
| CN1162650A (en) | Method for smelting sodium sulfate from refined complex antimony ore | |
| CA1125520A (en) | Process for precipitating iron as jarosite with a low non-ferrous metal content | |
| WO1988003912A1 (en) | Process for recovering metal values from ferrite wastes | |
| Beckstead et al. | Brine leaching of zinc leach residue |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |