Patents Represented by Attorney Robert A. Petrusek
  • Patent number: 4702896
    Abstract: An improved, substantially more energy efficient, thermal treatment process for use on relatively high organic content phosphate rock is herein taught wherein such rock is heated in two stages under controlled conditions to thereby yield an improved calcined product rendered more suitable for subsequent processing into wet-process phosphoric acid by, for example, acidulation with a mixture of phosphoric and sulfuric acids. The two-stage thermal treatment of the instant invention has been demonstrated to be especially beneficial when applied to an apatitic phosphate rock possessing a high content of organic matter and a high degree of carbonate substitution in the apatite crystal lattice thereof.
    Type: Grant
    Filed: September 2, 1986
    Date of Patent: October 27, 1987
    Assignee: Tennessee Valley Authority
    Inventor: Alexander D. Mair
  • Patent number: 4676821
    Abstract: The present invention teaches a technique and provides for apparatus eminently useful for reducing the amount of sulfur currently needed by industry to coat water-soluble fertilizer materials such as, for example, granular or prilled urea. A further advantage of and benefits derived from the practice of the instant invention relates to the production of sulfur-coated urea products which have substantially higher nitrogen values than do urea products produced by prior art processes.
    Type: Grant
    Filed: December 12, 1986
    Date of Patent: June 30, 1987
    Assignee: Tennessee Valley Authority
    Inventors: Larry L. Gullett, Charles L. Simmons
  • Patent number: 4676822
    Abstract: The herein described practice and operating procedures relating to the instant invention have demonstrated the utility and economic advantages of slightly acidic, neutral, and slightly basic fluid fertilizer solutions containing urea and the urease inhibitor thiophosphoryl triamide in preventing or at least substantially reducing the loss of ammoniacal nitrogen from soils to which such fluid fertilizers are often surface applied. The results of said testing procedures also demonstrate a new, novel, and heretofore unknown method of utilizing said thiophosphoryl triamide in conjunction with urea which method circumvents the problem usually encountered in the practice of prior art processes of rapid inhibitor decomposition in solid mixtures with urea.
    Type: Grant
    Filed: July 24, 1986
    Date of Patent: June 30, 1987
    Assignee: Tennessee Valley Authority
    Inventor: Joe Gautney
  • Patent number: 4670038
    Abstract: Test show that 2,2,4,4,6,6-hexaaminocyclotriphosphazatriene, 2-phenoxy-2,4,4,6,6-pentaaminocyclotriphosphazatriene, 2,4-diphenoxy-2,4,6,6-tetraaminocyclotriphosphazatriene and 2,4,6-triphenoxy-2,4,6-triaminocyclotriphosphazatriene (also frequently called phosphonitrilic derivatives) of the formula ##STR1## are highly effective inhibitors of urease activity in agricultural soil systems wherein(1) R.sub.1 . . . R.sub.3 '=NH.sub.2 or(2) R.sub.1 '=R.sub.2 '=R.sub.3 '=R.sub.2 =R.sub.3 =NH.sub.2 and R.sub.1 =OC.sub.6 H.sub.5 or(3) R.sub.1 '=R.sub.2 '=R.sub.3 '=R.sub.3 =NH.sub.2 and R.sub.1 =R.sub.2 =OC.sub.6 H.sub.5 or(4) R.sub.1 '=R.sub.2 '=R.sub.3 '=NH.sub.2 and R.sub.1 =R.sub.2 =R.sub.3 =OC.sub.6 H.sub.5.
    Type: Grant
    Filed: August 21, 1986
    Date of Patent: June 2, 1987
    Assignee: Tennessee Valley Authority
    Inventors: Ramiro Medina, Jack M. Sullivan
  • Patent number: 4648966
    Abstract: An improved phosphate ore beneficiation process wherein phosphate ore containing coarse, weathered dolomite in the flotation feed thereof is subjected to beneficiation as follows: The flotation feed is subjected to a rougher phosphate flotation step wherein it is treated with fatty acid and fuel oil and wherefrom is removed the coarse, weathered dolomite in one or more subsequent cleaner phosphate flotation steps without the use of additional flotation reagents added thereto; subjecting the float from said cleaner phosphate flotation step(s) to a sulfuric acid based partial deoiling step and then to a phosphate-carbonate flotation step wherefrom is collected a first fraction of the phosphate flotation feed values as underflow subjecting the overflow from said phosphate-carbonate flotation step to a sulfuric acid based total deoiling step wherefrom the resulting deoiled material from said total deoiling step is subsequently introduced and subjected to carbonate flotation step(s) using alkyl diphosphonic acid a
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: March 10, 1987
    Assignee: Tennessee Valley Authority
    Inventor: Shaung-shii Hsieh
  • Patent number: 4636303
    Abstract: A phosphate ore beneficiation process wherein phosphate ore containing coarse, weathered dolomite in the flotation feed thereof is subjected to beneficiation as follows: Said feed is sent to rougher phosphate flotation wherein it is treated with fatty acid and fuel oil and wherefrom is removed the coarse weathered dolomite in one or more cleaner phosphate flotations, without the use of additional flotation reagents added thereto, to thereby remove the coarse carbonate, i.e., dolomite fraction, which fraction would not otherwise float in subsequent carbonate flotation. In many instances this process effects reduction of the carbonate, as MgO contamination in the final concentrate, to less than about 1.0 percent by weight. Process feed can be prepared from the coarse pebble waste or the conventional flotation feed of the original phosphate matrix.
    Type: Grant
    Filed: October 7, 1985
    Date of Patent: January 13, 1987
    Assignee: Tennessee Valley Authority
    Inventor: Shuang-shii Hsieh
  • Patent number: 4619684
    Abstract: Process for producing diammonium phosphate (DAP) fertilizer from phosphoric and sulfuric acids, anhydrous ammonia, and water in a specially designed reactor operated at high pressures to granulate diammonium phosphate at low recycle ratios and with relatively small fossil fuel requirement drying per ton of product. Previously operated reactors employed pressures ranging from 0 to 10 psig pressures. This reactor operates at 40 to 80 psig. The process substantially increases production in existing DAP granulation plants and has helped reduce grade deficiencies. Also, use of this reactor for DAP production results in about the same levels of ammonia loss to the scrubber as the prior-art tank preneutralizer, higher operating factors, less maintenance and no transfer pump plugging. Operation is at a temperature of 300.degree. or more .degree.F., while the tank preneutralizer operates normally at 240.degree. F.
    Type: Grant
    Filed: March 24, 1986
    Date of Patent: October 28, 1986
    Assignee: Tennessee Valley Authority
    Inventors: David G. Salladay, Frank P. Achorn
  • Patent number: 4618691
    Abstract: Tests show that 2,2,4,4,6,6-hexaaminocyclotriphosphazatriene, 2-phenoxy-2,4,4,6,6-pentaaminocyclotriphosphazatriene, 2,4-diphenoxy-2,4,6,6-tetraaminocyclotriphosphazatriene and 2,4,6-triphenoxy-2,4,6-triaminocyclotriphosphazatriene (also frequently called phosphonitrilic derivatives) of the formula ##STR1## are highly effective inhibitors of urease activity in agricultural soil systems wherein(1) R.sub.1 . . . R.sub.3 '=NH.sub.2 or(2) R.sub.1 '=R.sub.2 '=R.sub.3 '=R.sub.2 =R.sub.3 =NH.sub.2 and R.sub.1 =OC.sub.6 H.sub.5 or(3) R.sub.1 '=R.sub.2 '=R.sub.3 '=R.sub.3 =NH.sub.2 and R.sub.1 =R.sub.2 =OC.sub.6 H.sub.5 or(4) R.sub.1 '=R.sub.2 '=R.sub.3 '=NH.sub.2 and R.sub.1 =R.sub.2 =R.sub.3 =OC.sub.6 H.sub.5.
    Type: Grant
    Filed: December 31, 1984
    Date of Patent: October 21, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Ramiro Medina, Jack M. Sullivan
  • Patent number: 4617048
    Abstract: A process for producing urea ammonium nitrate (UAN) sodium bentonite suspension from hot urea solution, hot ammonium nitrate solution and dry solid sodium bentonite clay. The dry sodium bentonite clay is added directly to the hot urea solution without the use of expensive chemical dispersants. There is no need for intermediate processing steps involving the dispersion of clay in water, said water normally containing expensive chemical dispersants. After the sodium bentonite has been dispersed in the hot urea solution, then, and only then can the hot ammonium nitrate solution be added. Unexpectedly, the order of addition of the feed material to this process is highly critical. This economical and innovative production process is readily adaptable to existing commercial nitrogen fertilizer production plants and has solved many of the problems which have kept sodium bentonite from being widely used in the production of suspension fertilizers.
    Type: Grant
    Filed: August 26, 1985
    Date of Patent: October 14, 1986
    Assignee: Tennessee Valley Authority
    Inventors: David G. Salladay, Donald L. Kachelman
  • Patent number: 4606897
    Abstract: Phosphate rock, containing appreciable quantities of organic impurities, is thermally treated under controlled conditions to fully utilize the fuel values of the organic matter contained therein. This process is beneficial for treating deposits of unaltered Idaho rock containing both higher grade phosphate rock and lower grade phosphatic shales and recovering therefrom substantially all the phosphate values as a rock product rendered more acceptable for acidulation to wet-process phosphoric acid.
    Type: Grant
    Filed: April 29, 1985
    Date of Patent: August 19, 1986
    Assignee: Tennessee Valley Authority
    Inventor: Alexander D. Mair
  • Patent number: 4601891
    Abstract: An improved process for the production of granular ammonium polyphosphate fertilizer of a nominal 11-56-0 grade resulting from the pressure ammoniation of phosphoric acid without the use of a preneutralizer and using a specially designed pipe reactor to effect coating and granulation of an anhydrous melt onto cascading granules of ammonium polyphosphate with polyphosphate contents thereof ranging from about 15 percent to 30 percent of the total P.sub.2 O.sub.5. The instant invention defines the operating parameters which allow for the practice of a process wherein there is essentially no degradation in the amount of P.sub.2 O.sub.5 values produced as polyphosphate in the melt as said melt is further processed in the remaining steps therein through the step of product recovery, i.e., we have discovered the parameters for operating a process wherein essentially no hydrolysis of the polyphosphate P.sub.2 O.sub.5 values in the melt occurs.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: July 22, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Kenneth E. McGill, Johnny R. Gamble
  • Patent number: 4600505
    Abstract: A flotation process is taught for beneficiating phosphate ores containing, as impurities, silica and alkaline earth metal carbonates, particularly dolomite. Using a single flotation stage, the phosphate values are recovered in the overflow and quite unexpectedly both the siliceous and the carbonate gangue minerals are simultaneously removed in the underflow. Prior to flotation, surfaces of the minerals in the phosphate ore are selectively sulfidized with an insoluble copper-containing metal sulfide, permitting use of sulfide mineral collecting reagents such as alkyl xanthates in the flotation step to achieve a high degree of selectivity.
    Type: Grant
    Filed: September 9, 1985
    Date of Patent: July 15, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Alexander D. Mair, Myra M. Soroczak
  • Patent number: 4589904
    Abstract: A process for granulating crystalline by-product ammonium sulfate, hereinafter referred to, for the sake of convenience, as A/S, to produce a product having excellent physical and chemical properties as they relate to the storage and handling thereof and also as they relate to the bulk blending of same with other fertilizer blend materials. The method involves introducing the crystalline by-product A/S feedstock, together with recycle material, into a conventional drum ammoniator granulator and granulating the mixture using A/S-sulfuric acid-alum solution and gaseous anhydrous ammonia to bind the crystals together by virtue of the fresh A/S produced and precipitated. Drying in a rotary drum dryer by countercurrent flow of hot gases instead of the more conventional cocurrent gas flow is required.
    Type: Grant
    Filed: August 26, 1985
    Date of Patent: May 20, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Cecil P. Harrison, Cullen G. Tittle
  • Patent number: 4588498
    Abstract: A flotation process is taught for beneficiating phosphate ores containing, as impurities, silica and alkaline earth metal carbonates, particularly dolomite. Using a single flotation stage, the phosphate values are recovered in the overflow and quite unexpectedly both the siliceous and the carbonate gangue minerals are simultaneously removed in the underflow. Prior to flotation, surfaces of the minerals in the phosphate ore are selectively sulfidized with an insoluble copper-containing metal sulfide, permitting use of sulfide mineral collecting reagents such as alkyl xanthates in the flotation step to achieve a high degree of selectivity.
    Type: Grant
    Filed: March 28, 1985
    Date of Patent: May 13, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Alexander D. Mair, Myra M. Soroczak
  • Patent number: 4587358
    Abstract: One approach to improving storage stability, particularly that attribute characterized by reduction in the tendency for caking during storage of freshly prepared urea particles such as granules, is to treat the surface areas of the freshly prepared particles/granules with appropriate amounts and kinds of conditioning agents. This approach does not address the problem of increasing the hardness of the particles to impart improved high-strength characteristics thereto. A second approach to this problem of improving storage stability of urea granules is to admix and/or react certain anticaking and hardness improving additives into or with the urea melt prior to the solidification of urea particulates therefrom. The instant invention is directed to this second approach of imparting to the ultimately prepared urea particles both improved anticaking and hardness (as opposed to being easily crushed, i.e., friable) characteristics by means of addition to the urea melt of certain additives.
    Type: Grant
    Filed: August 26, 1985
    Date of Patent: May 6, 1986
    Assignee: Tennessee Valley Authority
    Inventor: Glenn M. Blouin
  • Patent number: 4571435
    Abstract: A process for the preparation of nitrogen fertilizers, especially oxamide, either indirectly or directly from oxalate esters, including the regeneration of the quinone oxidant utilized in the formation of the above esters. The process teaches preparation of oxamide, a potential slow-release nitrogen fertilizer via the oxidative carbonylation of alcohols with carbon monoxide in the presence of a catalytic amount of a platinum group metal salt and an optionally substituted quinone (substituted or unsubstituted 2,5-cyclohexadiene-1,4-dione) followed by ammoniation of the filtered reaction mixture at room temperature, or below. High yields of isolated oxamide were obtained by regulating the temperature and pressure during the oxidative carbonylation and maintaining essentially anhydrous conditions throughout the process. In addition, nearly quantitative yields of the hydroquinones (1,4-dihydroxybenzenes) are recovered for recycle along with the solvents, or for other commercial uses.
    Type: Grant
    Filed: December 3, 1981
    Date of Patent: February 18, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Robert J. Radel, Jack M. Sullivan
  • Patent number: 4565625
    Abstract: A phosphate ore flotation process comprising subjecting a phosphate ore containing surface-activated silica and silicates to froth flotation in the presence of a fatty-acid collector, recovering the phosphate concentrate from the overflow; removing the fatty acid collector from the phosphate concentrate in the presence of a sulfuric acid deoiling agent; subjecting the phosphate concentrate to a reversed froth flotation in the presence of a silica collector and a modifier, said silica collector being an amine and said modifier being either alkyl diphosphonic acid, or being HF; removing the separated silica from the overflow; and recovering the phosphate product in the underflow. The process of the present invention not only overcomes the problems of activated silica flotation, but also results in greatly improved grade and/or recovery of phosphate product in comparison to present conventional phosphate ore flotation processing.
    Type: Grant
    Filed: December 10, 1984
    Date of Patent: January 21, 1986
    Assignee: Tennessee Valley Authority
    Inventors: Shuang-shii Hsieh, James R. Lehr
  • Patent number: 4557909
    Abstract: Phosphate rock is heated under controlled conditions to essentially eliminate organic impurities and sulfides from the rock and subsequently leached with water to substantially increase the porosity and surface area of the calcined solid and remove any traces of sulfide still remaining in the calcine. This process yields an improved calcined product rendered more suitable for acidulation to wet-process phosphoric acid and is beneficial for apatitic phosphate rocks possessing a moderate to high content of organic impurities and a high degree of carbonate substitution in the apatite crystal lattice.
    Type: Grant
    Filed: December 13, 1984
    Date of Patent: December 10, 1985
    Assignee: Tennessee Valley Authority
    Inventor: Alexander D. Mair
  • Patent number: 4531962
    Abstract: In the first embodiment of our invention, solution type fertilizers are produced by reacting phosphoric acid with urea-ammonium nitrate solution (35 percent CO{NH.sub.2 }.sub.2, 45 percent NH.sub.4 NO.sub.3, and 20 percent H.sub.2 O), and urea. In the second embodiment of our invention, the same solution is produced by reacting phosphoric acid with a urea-ammonium nitrate suspension that contains 36 percent nitrogen, 56 percent urea, and 29 percent ammonium nitrate. The ammonium nitrate portion of the nitrogen solution in said first embodiment reacts with the urea and phosphoric acid to produce urea nitrate (CO{NH}.sub.2.HNO.sub.3) and ammonium phosphate (probably NH.sub.4 H.sub.2 PO.sub.4). This solution contains rapidly available nitrate nitrogen as well as ammonium type nitrogen that is more slowly available than nitrate nitrogen. Similar results were obtained in said second embodiment when nitrogen solution and urea were reacted with sulfuric acid. The resulting solution contained CO(NH.sub.2).sub.2.HNO.
    Type: Grant
    Filed: June 4, 1984
    Date of Patent: July 30, 1985
    Assignee: Tennessee Valley Authority
    Inventors: Frank P. Achorn, Carl A. Cole, Jr.
  • Patent number: H38
    Abstract: A process for the preparation of urea and its derivatives by reacting CO, NO, and a hydrogen source over a supported noble metal catalyst at atmospheric pressure is described. Preferably, stoichiometric amounts of reactory gases are used. Reaction temperatures are in the range of 75.degree. C. to 225.degree. C.
    Type: Grant
    Filed: July 15, 1985
    Date of Patent: March 4, 1986
    Assignee: Tennesee Valley Authority
    Inventors: Robert J. Radel, Yong K. Kim