COLLECTOR COMPOSITION FOR ORE FLOTATION
United States Patent 3779380
Disclosed is a novel ore concentration process. The process involves the use of novel collectors in the flotation method for concentrating ore such, for example, as iron ore.
US Patent References:
Concentration of oxidized ores
Carnahan - May 1928 - 1671698
Process for breaking petroleum emulsions
Roberts - December 1935 - 2023976
Condensation product and method
Clocken - January 1940 - 2188885
Tungsten ore flotation
Gieseke - April 1945 - 2373305
Concentration of iron ores by froth flotation
Clemmons - February 1955 - 2701057
Concentration of oxidized ores
Carnahan - May 1928 - 1671698
Process for breaking petroleum emulsions
Roberts - December 1935 - 2023976
Condensation product and method
Clocken - January 1940 - 2188885
Tungsten ore flotation
Gieseke - April 1945 - 2373305
Concentration of iron ores by froth flotation
Clemmons - February 1955 - 2701057
Application Number:
05/188571
Publication Date:
12/18/1973
Filing Date:
10/12/1971
View Patent Images:
Export Citation:
Assignee:
Hercules Incorporated (Wilmington, DE)
Primary Class:
Other Classes:
252/61
International Classes:
B03D1/008; B03D1/004; B07B1/00
Field of Search:
209/166,167 252/61 260/97.5,404.8,398
US Patent References:
Primary Examiner:
Halper, Robert
Claims:
What I claim and desire to protect by Letters Patent is
1. In the process of separating finely ground hematite and phosphate minerals from their associated gangue by the froth flotation process in the presence of a collector, the improvement wherein the collector employed is a composition, liquid at room temperature, which consists essentially of, by weight, (A) from about 95 percent to about 80 percent of at least one C12 -C22 monobasic fatty acid that is liquid at room temperature and (B) from about 5% to about 20 percent of an adduct selected from the group consisting of (1) acrylic acid adducts of at least one C12 -C22 monobasic fatty acid containing at least one carbon to carbon double bond, (2) hydrolyzed maleic anhydride adducts of at least one C12 -C22 monobasic fatty acid containing at least one carbon double bond, and (3) substituted succinic acid having the formula ##SPC2##
2. The process of claim 1 wherein component (A) is tall oil fatty acid.
3. The process of claim 1 wherein the adduct is an acrylic acid adduct of at least one C12 -C22 monobasic fatty acid containing at least one carbon to carbon double bond.
4. The process of claim 1 wherein the adduct is the hydrolyzed maleic anhydride adduct of at least one C12 -C22 monobasic fatty acid containing at least one carbon to carbon double bond.
5. The process of claim 1 wherein the adduct is a substituted succinic acid having the formula ##SPC3##
6. The process of claim 1 wherein the adduct is the acrylic acid adduct of conjugated linoleic acid.
7. The process of claim 1 wherein the adduct is the hydrolyzed maleic anhydride adduct of conjugated linoleic acid.
8. The process of claim 1 wherein the adduct is the hydrolyzed maleic anhydride adduct of oleic acid.
9. The process of claim 1 wherein the adduct is isooctadecenyl succinic acid.
10. The process of claim 6 wherein component (A) is tall oil fatty acid.
11. The process of claim 7 wherein component (A) is tall oil fatty acid.
12. The process of claim 8 wherein component (A) is tall oil fatty acid.
13. The process of claim 9 wherein component (A) is tall oil fatty acid.
1. In the process of separating finely ground hematite and phosphate minerals from their associated gangue by the froth flotation process in the presence of a collector, the improvement wherein the collector employed is a composition, liquid at room temperature, which consists essentially of, by weight, (A) from about 95 percent to about 80 percent of at least one C12 -C22 monobasic fatty acid that is liquid at room temperature and (B) from about 5% to about 20 percent of an adduct selected from the group consisting of (1) acrylic acid adducts of at least one C12 -C22 monobasic fatty acid containing at least one carbon to carbon double bond, (2) hydrolyzed maleic anhydride adducts of at least one C12 -C22 monobasic fatty acid containing at least one carbon double bond, and (3) substituted succinic acid having the formula ##SPC2##
2. The process of claim 1 wherein component (A) is tall oil fatty acid.
3. The process of claim 1 wherein the adduct is an acrylic acid adduct of at least one C12 -C22 monobasic fatty acid containing at least one carbon to carbon double bond.
4. The process of claim 1 wherein the adduct is the hydrolyzed maleic anhydride adduct of at least one C12 -C22 monobasic fatty acid containing at least one carbon to carbon double bond.
5. The process of claim 1 wherein the adduct is a substituted succinic acid having the formula ##SPC3##
6. The process of claim 1 wherein the adduct is the acrylic acid adduct of conjugated linoleic acid.
7. The process of claim 1 wherein the adduct is the hydrolyzed maleic anhydride adduct of conjugated linoleic acid.
8. The process of claim 1 wherein the adduct is the hydrolyzed maleic anhydride adduct of oleic acid.
9. The process of claim 1 wherein the adduct is isooctadecenyl succinic acid.
10. The process of claim 6 wherein component (A) is tall oil fatty acid.
11. The process of claim 7 wherein component (A) is tall oil fatty acid.
12. The process of claim 8 wherein component (A) is tall oil fatty acid.
13. The process of claim 9 wherein component (A) is tall oil fatty acid.
Description:
This invention relates to ore beneficiation and particularly to the froth flotation process for concentrating ores such as iron ore. Particularly, this invention involves the use of novel collectors in the froth flotation process for concentrating ores.
In the flotation of ores such, for example, as iron ore and the like, it is usual practice to use collecting agents (collectors) to float the valuable ore or mineral from the gangue. Collectors commonly used for this purpose include tall oil, tall oil fatty acids, petroleum sulfonates, turkey red oil, and saponified tall oil pitch. Other flotation agents such as frothers and modifying agents are usually employed along with collectors to enhance the activity thereof.
In the concentration of iron minerals, such as specular hematite which occurs in the Jaspar ores of northern Michigan, it is the usual practice to employ tall oil fatty acids low in rosin content as collectors in the flotation of the hematite. Details of the procedure used in one of the large operations of this type is reported by Johnson and Bjorne in Milling Methods of the Americas, Gordon and Breach Science Publishers (1964). The use of fatty acids and resin acids as collectors for iron oxides is reported in Bureau of Mines Report of Investigations 5498 by S. R. B. Cooke and Walter Nummela, United States Department of the Interior, 1959.
The flotation process of this invention involves the use of novel collectors which provide for improved ore concentration.
The novel collectors employed in this invention are compositions that are liquid at room temperature (about 23° C.) and consist essentially of, by weight, (A) from about 95 to about 80 percent of at least one C 12 -C 22 monobasic fatty acid that is liquid at room temperature and (B) from about 5 to about 20 percent of an adduct selected from the group consisting of (1) acrylic acid adducts of at least one C 12 -C 22 monobasic fatty acid containing at least one carbon to carbon double bond, (2) hydrolyzed maleic anhydride adducts of at least one C 12 -C 22 monobasic fatty acid containing at least one carbon to carbon double bond, and (3) substituted succinic acids.
Monobasic C 12 -C 22 acids containing at least one carbon to carbon double bond that are liquid at room temperature are known in the art and includes lauroleic acid (C 12 ), myristoleic acid (C 14 ), palmitoleic acid (C 16 ), oleic acid (C 18 ), erucic acid (C 22 ), linoleic acid (C 18 ), linolenic acid (C 18 ), and eleostearic acid (C 18 ).
A convenient method of preparing the compositions used as collectors in this invention is to start with a fatty acid mixture such as tall oil fatty acids derived by fractional distillation of tall oil. The tall oil fatty acids will have a substantial content of monobasic fatty acids having at least one carbon to carbon double bond. The tall oil fatty acids can be adducted with the desired amount of acrylic acid or maleic anhydride or both to provide the desired composition for use as a collector. Adducts prepared by use of maleic anhydride are subsequently subjected to hydrolysis to provide a hydrolyzed maleic anhydride adduct. Hydrolysis is easily and readily accomplished and methods of hydrolysis are well known to those skilled in the art. Thus, for example, hydrolysis of a maleic anhydride adduct can be attained by heating the adduct in water at elevated temperature of the order of about 90° C. for a period of time sufficient to effect hydrolysis, usually about one hour.
Analysis of a commercially available fatty acid fraction obtained by the fractional distillation of tall oil is set forth below. This analysis is given for examplary purposes only.
Palmitic acid 5.7% Palmitoleic acid 1.5% Stearic acid 1.4% Oleic acid 30.7% Linoleic acid 42.4% Docosenoic acid 2.5% Linolenic acid 5.5% Rosin acids 7.0% Unsaponifiables 2.5%
As is well known to those skilled in the art the above proportions will vary depending on the source of tall oil and the fraction taken during distillation.
Palmitic acid has the formula CH 3 (CH 2 ) 14 COOH; palmitoleic acid has the formula CH 3 (CH 2 ) 5 CH=CH(CH 2 ) 7 COOH; stearic acid has the formula CH 3 (CH 2 ) 16 COOH; oleic acid has the formula CH 3 (CH 2 ) 7 CH=CH(CH 2 ) 7 COOH. Linolenic acid is a C 18 polyunsaturated acid having three unconjugated double bonds such as 5,9,12-octadecatrienoic acid and 9,12,15-octadecatrienoic acid. Linoleic acid is a C 18 polyunsaturated acid having two double bonds and exists in both the unconjugated and conjugated forms such as 9,12-linoleic acid and 9,11-linoleic acid.
Substituted succinic acids used in this invention have the formula ##SPC1##
wherein R is a hydrocarbon radical selected from the group consisting of an alkyl, alkenyl, aralkyl, and aralkenyl having from 8 through 18 carbon atoms. Specific examples of such compounds include isooctadecenyl succinic acid, n-hexadecenyl succinic acid, dodecenyl succinic acid, dodecyl succinic acid, decenyl succinic acid, octenyl succinic acid, nonenyl succinic acid, triisobutenyl succinic acid and isomers of the above enumerated acids.
The following examples are illustrative of this invention. In the examples percent is by weight.
Example 1
A six hundred ten-gram sample of 8-mesh specular hematite ore having an iron content of about 37 percent is subjected to grinding in a ball mill along with 550 ml. of distilled water for 8 minutes to provide a slurry (referred to in the art as "pulp") so that most of the pulp will pass through a 65-mesh screen. The pulp is then transferred to a standard 600-gram Fagergren flotation cell. Enough water is added to the cell to essentially fill it. This is followed by addition of 2 ml. of a 5 percent aqueous sodium metasilicate solution. The pulp is agitated for 20 seconds and then allowed to settle for 3-1/4 minutes. Slimes are siphoned off. This settling and siphoning off of slimes is then repeated once. The amount of slimes removed is about 7.3 percent of the sample (original sample weight 610 g.) and of the slimes about 16.48 percent thereof is iron. The deslimed pulp is transferred to a conditioning cell and the pH of the pulp is adjusted to about 7.7 with sulfuric acid. The solids content of the pulp at this stage is about 75 percent. The pulp is conditioned for 5 minutes using as a collector tall oil fatty acids having an acid number of 190 and an iodine number of 130. The amount of collector employed is equivalent to 0.83 lb. of collector per ton of starting ore sample. The fatty acid content of the tall oil fatty acids is 90.5 percent, the resin acid content is 7 percent, and the content of unsaponifiables is 2.5 percent. During the 5-minute conditioning period the pulp is agitated by means of a blade agitator operating at a speed of about 800 r.p.m. The conditioned pulp is then placed in a Fagergren cell and diluted with distilled water to a solids concentration of about 30 percent. A rougher float is removed for a period of about 3-1/2 minutes. The rougher tail removed during this period amounts to about 33.1 percent of the starting ore sample, of this tail about 9.97 percent thereof is iron. The rougher float is again placed in the Fagergren cell and diluted with distilled water to a solids content of about 30 percent and an ore concentrate (first cleaner float) removed for about 3-1/2 minutes. A cleaner tail is removed during this period and the amount thereof is about 9.5 percent of the weight of the starting ore sample, and of this amount, about 17.52 percent thereof is iron. The concentrate recovered is about 50.1 percent of the weight of the starting ore sample and of this amount about 61.89 percent thereof is iron. As above set forth, the amount of iron present in the original 610-gram ore sample is about 37 percent. By the process of this example about 83.4 percent of the iron present in the sample is recovered in the ore concentrate.
Example 2
Example 1 is repeated using as collector a composition which is derived by adducting maleic anhydride with a tall oil fatty acid containing about 98.4 percent fatty acids (6.3 percent of which is conjugated linoleic acid), about 0.7 precent resin acids, and about 0.9 percent unsaponifiables. The composition is derived by heating at 110° C. for about 2 hours a mixture of 1,000 grams of the tall oil fatty acid, 35 grams of maleic anhydride, and 0.5 gram of iodine, and subsequently hydrolyzing the reaction product. The resulting composition (after hydrolysis of the adducted maleic anhydride is complete) has an acid number of 207 and has the following fatty acid composition: (A) about 3.3 percent adducted fatty acids, primarily adducted linoleic acid, and (B) about 96.7 percent of unadducted fatty acids. The amount of collector employed is equivalent to about 0.82 lb. per ton of starting ore sample. The concentrate of this example is about 51.4 percent by weight of the starting ore sample and of this amount, about 62.29 percent is iron. By using the collector of this example about 87.2 percent of the iron present in the starting ore sample is recovered.
Example 3
Example 2 is repeated except that the collector is used in an amount equivalent to 0.83 lb. per ton of ore sample. The collector used in this example is prepared in the same manner as that of Example 2 and has an acid number of 204. In addition there is no adjustment of pH made before conditioning. In this example the pH of the pulp varies between 9 and 9.3 during treatment. The concentrate of this example is about 51.2 percent by weight of the starting ore sample and of this amount about 59.24 percent is iron. By using the collector of this example, in the amount specified, about 87.9 percent of the iron present in the starting ore sample is recovered in the concentrate.
Example 4
Example 3 is repeated with the exception that the amount of collector employed is equivalent to 0.81 lb. per ton of ore. The collector employed is a portion of that prepared for use in Example 2. The concentrate of this example is about 48.8 percent of the starting ore, and of this amount, about 62.03 percent is iron. About 82.8 percent of the iron present in the starting ore sample is recovered in the concentrate in this example.
Example 5
Example 1 is repeated using a different lot of hematite ore and with two changes made in the procedure. The iron content of the ore is about 37 percent by weight, based on the total weight of the ore sample used. The weight of the ore sample is 610 grams. The first change in the procedure is that the ore is ground for 7 minutes in the ball mill and the settling time in the desliming step is 2-3/4 minutes. The second change is that no adjustment is made in the pH of the pulp in the conditioning cell. In this example the collector is prepared by thoroughly admixing 10 percent by weight of acrylic acid adduct of 9,11-linoleic acid and 90 percent, by weight, of a tall oil fatty acid having the following composition: 90.5 percent fatty acids, 7 percent rosin acids, and 2.5 percent unsaponifiables. The amount of collector employed in this example is equivalent to 0.41 lb. per ton of ore sample. The concentrate of this example is about 45.5 percent by weight of the starting ore sample and of this amount about 64.1 percent is iron. By using the collector of this example about 79.5 percent of the iron present in the starting ore sample is recovered in the concentrate.
Example 6
Example 5 is repeated with the exception that the pulp is adjusted to a pH 7.5-7.6 before conditioning. In addition the collector is conditioned with the pulp more vigorously by increasing the mixer speed from 800 r.p.m. to 1,350 r.p.m. In this example the collector is prepared by thoroughly admixing 10 percent by weight of hydrolyzed maleic anhydride adduct of 9,11-linoleic acid and 90 percent, by weight, of a tall oil fatty acid having the following composition: 90.5 percent fatty acids, 7 percent rosin acids, and 2.5 percent unsaponifiables. The amount of collector employed in this example is equivalent to 0.72 lb. per ton of ore sample. The concentrate of this example is about 48.8 percent by weight of the starting ore sample and of this amount, about 62.9 percent is iron. By using the collector of this example about 86.5 percent of the iron present in the starting ore sample is recovered in the concentrate. In this example the first cleaner float is run through the Fagergren cell again to provide the concentrate (second cleaner float) on which the above analyses are made.
Example 7
Example 6 is repeated using as the collector the same components of the collector of Example 6 in different proportions. The collector of this example is prepared by thoroughly admixing 7 percent by weight of hydrolyzed maleic anhydride adduct of 9,11-linoleic acid and 93 percent by weight of tall oil fatty acid having the composition: 90.5 percent fatty acids, 7 percent rosin acids, and 2.5 percent unsaponifiables. The amount of collector employed in this example is equivalent to 0.74 lb. per ton of ore sample. The concentrate of this example is about 48.1 percent by weight of the starting ore sample and of this amount about 62.8 percent is iron. In this example 85.8 percent of the iron present in the starting ore sample is recovered in the concentrate.
The collectors of this invention may be used generally in the flotation beneficiation of ores but is most advantageously employed on iron ores, oxide ores and nonmetallic ores such, for example, as in the flotation of calcite, fluorite, barite, gypsum, spodumene, ilmenite, chromite, magnesite, hematite, and the like. Example 8 below is illustrative of the use of the novel collectors of this invention in the flotation of phosphate.
Example 8
Six hundred sixty-five grams of wet Florida phosphate rock of -35 + 150 mesh size is given a mild scrubbing action for 2 minutes in a laboratory size attrition cell. The phosphate rock is washed with fresh water until the water remains clear. At a 70 percent solids concentration the phosphate rock is conditioned for 2 minutes in a 2-liter stainless steel beaker with gentle agitation with (1) sodium hydroxide in an amount equivalent to about 0.39 lb. per ton of phosphate rock, (2) No. 2 fuel oil in an amount equivalent to 1 lb. per ton of phosphate rock, and (3) the collector used in Example 2 in an amount equivalent to about 0.35 lb. per ton of phosphate rock. The phosphate rock is floated in a standard Fagergren cell with a 93 percent phosphate recovery.
Example 9
A composition is prepared by thoroughly admixing (1) 90 parts by weight of tall oil fatty acid of the composition: 90.5 percent fatty acids, 7.0 percent rosin acids, and 2.5 percent unsaponifiables, and (2) 10 parts by weight of isooctadecenylsuccinic acid. This composition when employed in a manner similar to that of Example 1 functions as a highly satisfactory collector.
Example 10
An adduct is prepared by reacting 100 grams of oleic acid and 27 grams of maleic anhydride at 220° C. for 2 hours, followed by hydrolysis. About 10 parts by weight of this adduct is thoroughly admixed with 90 parts by weight of the tall oil fatty acid of Example 5 to provide a highly satisfactory collector for use in the method of this invention.
While adducts with fumaric acid can be used in admixture with fatty acids to provide a composition that will function as a collector, the results obtainable by the use thereof are not as satisfactory as those obtained by use of the novel collectors of this invention.
The novel collectors of this invention can be added to the flotation pulp as such or as aqueous solutions of a soluble salt thereof such, for example, as the sodium or potassium salt. A pH of from about 7 to about 8 in the conditioning step is preferred in the process of this invention, and the conditioning step should be carried out for a period of time sufficient to obtain good contact and adsorption of the collector on the mineral surface. The period of time required is well within the skill of those versed in the art.
It is to be understood that the above description and working examples are illustrative of this invention and not in limitation thereof.
In the flotation of ores such, for example, as iron ore and the like, it is usual practice to use collecting agents (collectors) to float the valuable ore or mineral from the gangue. Collectors commonly used for this purpose include tall oil, tall oil fatty acids, petroleum sulfonates, turkey red oil, and saponified tall oil pitch. Other flotation agents such as frothers and modifying agents are usually employed along with collectors to enhance the activity thereof.
In the concentration of iron minerals, such as specular hematite which occurs in the Jaspar ores of northern Michigan, it is the usual practice to employ tall oil fatty acids low in rosin content as collectors in the flotation of the hematite. Details of the procedure used in one of the large operations of this type is reported by Johnson and Bjorne in Milling Methods of the Americas, Gordon and Breach Science Publishers (1964). The use of fatty acids and resin acids as collectors for iron oxides is reported in Bureau of Mines Report of Investigations 5498 by S. R. B. Cooke and Walter Nummela, United States Department of the Interior, 1959.
The flotation process of this invention involves the use of novel collectors which provide for improved ore concentration.
The novel collectors employed in this invention are compositions that are liquid at room temperature (about 23° C.) and consist essentially of, by weight, (A) from about 95 to about 80 percent of at least one C 12 -C 22 monobasic fatty acid that is liquid at room temperature and (B) from about 5 to about 20 percent of an adduct selected from the group consisting of (1) acrylic acid adducts of at least one C 12 -C 22 monobasic fatty acid containing at least one carbon to carbon double bond, (2) hydrolyzed maleic anhydride adducts of at least one C 12 -C 22 monobasic fatty acid containing at least one carbon to carbon double bond, and (3) substituted succinic acids.
Monobasic C 12 -C 22 acids containing at least one carbon to carbon double bond that are liquid at room temperature are known in the art and includes lauroleic acid (C 12 ), myristoleic acid (C 14 ), palmitoleic acid (C 16 ), oleic acid (C 18 ), erucic acid (C 22 ), linoleic acid (C 18 ), linolenic acid (C 18 ), and eleostearic acid (C 18 ).
A convenient method of preparing the compositions used as collectors in this invention is to start with a fatty acid mixture such as tall oil fatty acids derived by fractional distillation of tall oil. The tall oil fatty acids will have a substantial content of monobasic fatty acids having at least one carbon to carbon double bond. The tall oil fatty acids can be adducted with the desired amount of acrylic acid or maleic anhydride or both to provide the desired composition for use as a collector. Adducts prepared by use of maleic anhydride are subsequently subjected to hydrolysis to provide a hydrolyzed maleic anhydride adduct. Hydrolysis is easily and readily accomplished and methods of hydrolysis are well known to those skilled in the art. Thus, for example, hydrolysis of a maleic anhydride adduct can be attained by heating the adduct in water at elevated temperature of the order of about 90° C. for a period of time sufficient to effect hydrolysis, usually about one hour.
Analysis of a commercially available fatty acid fraction obtained by the fractional distillation of tall oil is set forth below. This analysis is given for examplary purposes only.
Palmitic acid 5.7% Palmitoleic acid 1.5% Stearic acid 1.4% Oleic acid 30.7% Linoleic acid 42.4% Docosenoic acid 2.5% Linolenic acid 5.5% Rosin acids 7.0% Unsaponifiables 2.5%
As is well known to those skilled in the art the above proportions will vary depending on the source of tall oil and the fraction taken during distillation.
Palmitic acid has the formula CH 3 (CH 2 ) 14 COOH; palmitoleic acid has the formula CH 3 (CH 2 ) 5 CH=CH(CH 2 ) 7 COOH; stearic acid has the formula CH 3 (CH 2 ) 16 COOH; oleic acid has the formula CH 3 (CH 2 ) 7 CH=CH(CH 2 ) 7 COOH. Linolenic acid is a C 18 polyunsaturated acid having three unconjugated double bonds such as 5,9,12-octadecatrienoic acid and 9,12,15-octadecatrienoic acid. Linoleic acid is a C 18 polyunsaturated acid having two double bonds and exists in both the unconjugated and conjugated forms such as 9,12-linoleic acid and 9,11-linoleic acid.
Substituted succinic acids used in this invention have the formula ##SPC1##
wherein R is a hydrocarbon radical selected from the group consisting of an alkyl, alkenyl, aralkyl, and aralkenyl having from 8 through 18 carbon atoms. Specific examples of such compounds include isooctadecenyl succinic acid, n-hexadecenyl succinic acid, dodecenyl succinic acid, dodecyl succinic acid, decenyl succinic acid, octenyl succinic acid, nonenyl succinic acid, triisobutenyl succinic acid and isomers of the above enumerated acids.
The following examples are illustrative of this invention. In the examples percent is by weight.
Example 1
A six hundred ten-gram sample of 8-mesh specular hematite ore having an iron content of about 37 percent is subjected to grinding in a ball mill along with 550 ml. of distilled water for 8 minutes to provide a slurry (referred to in the art as "pulp") so that most of the pulp will pass through a 65-mesh screen. The pulp is then transferred to a standard 600-gram Fagergren flotation cell. Enough water is added to the cell to essentially fill it. This is followed by addition of 2 ml. of a 5 percent aqueous sodium metasilicate solution. The pulp is agitated for 20 seconds and then allowed to settle for 3-1/4 minutes. Slimes are siphoned off. This settling and siphoning off of slimes is then repeated once. The amount of slimes removed is about 7.3 percent of the sample (original sample weight 610 g.) and of the slimes about 16.48 percent thereof is iron. The deslimed pulp is transferred to a conditioning cell and the pH of the pulp is adjusted to about 7.7 with sulfuric acid. The solids content of the pulp at this stage is about 75 percent. The pulp is conditioned for 5 minutes using as a collector tall oil fatty acids having an acid number of 190 and an iodine number of 130. The amount of collector employed is equivalent to 0.83 lb. of collector per ton of starting ore sample. The fatty acid content of the tall oil fatty acids is 90.5 percent, the resin acid content is 7 percent, and the content of unsaponifiables is 2.5 percent. During the 5-minute conditioning period the pulp is agitated by means of a blade agitator operating at a speed of about 800 r.p.m. The conditioned pulp is then placed in a Fagergren cell and diluted with distilled water to a solids concentration of about 30 percent. A rougher float is removed for a period of about 3-1/2 minutes. The rougher tail removed during this period amounts to about 33.1 percent of the starting ore sample, of this tail about 9.97 percent thereof is iron. The rougher float is again placed in the Fagergren cell and diluted with distilled water to a solids content of about 30 percent and an ore concentrate (first cleaner float) removed for about 3-1/2 minutes. A cleaner tail is removed during this period and the amount thereof is about 9.5 percent of the weight of the starting ore sample, and of this amount, about 17.52 percent thereof is iron. The concentrate recovered is about 50.1 percent of the weight of the starting ore sample and of this amount about 61.89 percent thereof is iron. As above set forth, the amount of iron present in the original 610-gram ore sample is about 37 percent. By the process of this example about 83.4 percent of the iron present in the sample is recovered in the ore concentrate.
Example 2
Example 1 is repeated using as collector a composition which is derived by adducting maleic anhydride with a tall oil fatty acid containing about 98.4 percent fatty acids (6.3 percent of which is conjugated linoleic acid), about 0.7 precent resin acids, and about 0.9 percent unsaponifiables. The composition is derived by heating at 110° C. for about 2 hours a mixture of 1,000 grams of the tall oil fatty acid, 35 grams of maleic anhydride, and 0.5 gram of iodine, and subsequently hydrolyzing the reaction product. The resulting composition (after hydrolysis of the adducted maleic anhydride is complete) has an acid number of 207 and has the following fatty acid composition: (A) about 3.3 percent adducted fatty acids, primarily adducted linoleic acid, and (B) about 96.7 percent of unadducted fatty acids. The amount of collector employed is equivalent to about 0.82 lb. per ton of starting ore sample. The concentrate of this example is about 51.4 percent by weight of the starting ore sample and of this amount, about 62.29 percent is iron. By using the collector of this example about 87.2 percent of the iron present in the starting ore sample is recovered.
Example 3
Example 2 is repeated except that the collector is used in an amount equivalent to 0.83 lb. per ton of ore sample. The collector used in this example is prepared in the same manner as that of Example 2 and has an acid number of 204. In addition there is no adjustment of pH made before conditioning. In this example the pH of the pulp varies between 9 and 9.3 during treatment. The concentrate of this example is about 51.2 percent by weight of the starting ore sample and of this amount about 59.24 percent is iron. By using the collector of this example, in the amount specified, about 87.9 percent of the iron present in the starting ore sample is recovered in the concentrate.
Example 4
Example 3 is repeated with the exception that the amount of collector employed is equivalent to 0.81 lb. per ton of ore. The collector employed is a portion of that prepared for use in Example 2. The concentrate of this example is about 48.8 percent of the starting ore, and of this amount, about 62.03 percent is iron. About 82.8 percent of the iron present in the starting ore sample is recovered in the concentrate in this example.
Example 5
Example 1 is repeated using a different lot of hematite ore and with two changes made in the procedure. The iron content of the ore is about 37 percent by weight, based on the total weight of the ore sample used. The weight of the ore sample is 610 grams. The first change in the procedure is that the ore is ground for 7 minutes in the ball mill and the settling time in the desliming step is 2-3/4 minutes. The second change is that no adjustment is made in the pH of the pulp in the conditioning cell. In this example the collector is prepared by thoroughly admixing 10 percent by weight of acrylic acid adduct of 9,11-linoleic acid and 90 percent, by weight, of a tall oil fatty acid having the following composition: 90.5 percent fatty acids, 7 percent rosin acids, and 2.5 percent unsaponifiables. The amount of collector employed in this example is equivalent to 0.41 lb. per ton of ore sample. The concentrate of this example is about 45.5 percent by weight of the starting ore sample and of this amount about 64.1 percent is iron. By using the collector of this example about 79.5 percent of the iron present in the starting ore sample is recovered in the concentrate.
Example 6
Example 5 is repeated with the exception that the pulp is adjusted to a pH 7.5-7.6 before conditioning. In addition the collector is conditioned with the pulp more vigorously by increasing the mixer speed from 800 r.p.m. to 1,350 r.p.m. In this example the collector is prepared by thoroughly admixing 10 percent by weight of hydrolyzed maleic anhydride adduct of 9,11-linoleic acid and 90 percent, by weight, of a tall oil fatty acid having the following composition: 90.5 percent fatty acids, 7 percent rosin acids, and 2.5 percent unsaponifiables. The amount of collector employed in this example is equivalent to 0.72 lb. per ton of ore sample. The concentrate of this example is about 48.8 percent by weight of the starting ore sample and of this amount, about 62.9 percent is iron. By using the collector of this example about 86.5 percent of the iron present in the starting ore sample is recovered in the concentrate. In this example the first cleaner float is run through the Fagergren cell again to provide the concentrate (second cleaner float) on which the above analyses are made.
Example 7
Example 6 is repeated using as the collector the same components of the collector of Example 6 in different proportions. The collector of this example is prepared by thoroughly admixing 7 percent by weight of hydrolyzed maleic anhydride adduct of 9,11-linoleic acid and 93 percent by weight of tall oil fatty acid having the composition: 90.5 percent fatty acids, 7 percent rosin acids, and 2.5 percent unsaponifiables. The amount of collector employed in this example is equivalent to 0.74 lb. per ton of ore sample. The concentrate of this example is about 48.1 percent by weight of the starting ore sample and of this amount about 62.8 percent is iron. In this example 85.8 percent of the iron present in the starting ore sample is recovered in the concentrate.
The collectors of this invention may be used generally in the flotation beneficiation of ores but is most advantageously employed on iron ores, oxide ores and nonmetallic ores such, for example, as in the flotation of calcite, fluorite, barite, gypsum, spodumene, ilmenite, chromite, magnesite, hematite, and the like. Example 8 below is illustrative of the use of the novel collectors of this invention in the flotation of phosphate.
Example 8
Six hundred sixty-five grams of wet Florida phosphate rock of -35 + 150 mesh size is given a mild scrubbing action for 2 minutes in a laboratory size attrition cell. The phosphate rock is washed with fresh water until the water remains clear. At a 70 percent solids concentration the phosphate rock is conditioned for 2 minutes in a 2-liter stainless steel beaker with gentle agitation with (1) sodium hydroxide in an amount equivalent to about 0.39 lb. per ton of phosphate rock, (2) No. 2 fuel oil in an amount equivalent to 1 lb. per ton of phosphate rock, and (3) the collector used in Example 2 in an amount equivalent to about 0.35 lb. per ton of phosphate rock. The phosphate rock is floated in a standard Fagergren cell with a 93 percent phosphate recovery.
Example 9
A composition is prepared by thoroughly admixing (1) 90 parts by weight of tall oil fatty acid of the composition: 90.5 percent fatty acids, 7.0 percent rosin acids, and 2.5 percent unsaponifiables, and (2) 10 parts by weight of isooctadecenylsuccinic acid. This composition when employed in a manner similar to that of Example 1 functions as a highly satisfactory collector.
Example 10
An adduct is prepared by reacting 100 grams of oleic acid and 27 grams of maleic anhydride at 220° C. for 2 hours, followed by hydrolysis. About 10 parts by weight of this adduct is thoroughly admixed with 90 parts by weight of the tall oil fatty acid of Example 5 to provide a highly satisfactory collector for use in the method of this invention.
While adducts with fumaric acid can be used in admixture with fatty acids to provide a composition that will function as a collector, the results obtainable by the use thereof are not as satisfactory as those obtained by use of the novel collectors of this invention.
The novel collectors of this invention can be added to the flotation pulp as such or as aqueous solutions of a soluble salt thereof such, for example, as the sodium or potassium salt. A pH of from about 7 to about 8 in the conditioning step is preferred in the process of this invention, and the conditioning step should be carried out for a period of time sufficient to obtain good contact and adsorption of the collector on the mineral surface. The period of time required is well within the skill of those versed in the art.
It is to be understood that the above description and working examples are illustrative of this invention and not in limitation thereof.