IL46276A - Water-soluble npk fertilizers and method of manufacturing them - Google Patents

Abstract

PURPOSE: To monitor the volume water content of a fluid by utilizing a variable mode microwave. CONSTITUTION: A microwave source 3 supplies microwave energy to a first antenna 7 and the antenna 7 supplies the energy to a fluid sample in a testing cell 8. A second antenna 9 receives the microwave energy passed through the sample. A detector 22 detects the received microwave energy and outputs a signal indicating the detected energy. An indicator 44 indicates the water content of the sample in accordance with the power of the received signal, the phase difference between the transmitted microwave energy and received microwave energy, and internally recorded calibration data only on waver and only on oil[JPS5099862A]

Description

NPK fertilizors and of manufacturing them Triomf Limited Johannesburg f Transvaal Republic of South Africa Inventors Johannes and Jacobus Petrue VAN DEVENTER THIS Invention relates to water soluble fertilizers and a method for manufacturing the The growing demand for the use of sol id fertil izers for direct appl ication through and drip Irrigation systems has been accompanied by a search for fertil izers free of the disadvantages normal ly found 1n mixed sol id fertil izer materials currently on the Often fertil izers of this type are not completely soluble in water and undissolved residues tend to block spraying Certain attempts have been made to overcome these disadvantages Including using Individual soluble fertil izer compounds and making mixed fertil The preparation of the latter Is often an elaborate process and some of the izers are poorly 1n although 1t has been known to mix urea and phosphoric 1n stoichiometric proportions to produce a water soluble urea phosphate id 1t 1s however not possible to vary the nitrogen to phosphorus ratios from mixture to mixture and thus vary the fertil izer compositions and at the same time obtain a composition which 1s whol ly A related type of izer 1s disclosed 1n Patent compound stated to relate to a quick release chemical fertil izer which can be appl ied to lawns 1n large quantities Injury to This compound which 1s prepared from urea potassium phosphoric and anhydrous ammonia differs from the fertilizer compound of the present Invention 1n that the final product does not Include any free urea phosphoric acid The reason for 1s that an excess of ammonia 1s employed which consumes all the available phosphoric thus preventing the latter from reacting with available The specification 1s silent on the question of the of the final but because of the excess this value should be relatively The product of the clearly intended for use 1n the and the specification accordingly Is on the question of the solubility of the final However It has been found that the addition of a potassium sal t with or without certain othe additives has enabled water soluble mixed fertil izer compositions to be made which are wholly sol Depending on the method which the constituent parts of the composition are mixed 1t ible to the to phosphorus the ion and obtain compositions are wholly Accordingly it is an object of the present invention to provide a fertilizer composition in solid and a method of manufacture which the applicant believes will have certain advantages over the known According to the invention a method for manufacturing a water soluble mixed fertilizer composition in solid form includes the steps of adding urea to phosphoric adding at least one potassium salt to the resultant mixture and agitating the Further according o invention the method includes the steps of dissolving urea in phosphoric acid to solution of urea phosphoric adduc adding one or more potassium salts to the solution agitating the cooling the mixture thus formed to a temperature which undissolved salts not settle out the to this form of invention is essential that the temperature to which the mixture cooled must not exceed to ensure that the mixture viscous to minimise of undissol the hand must be taken o the mixture only until the v cosity is such out solids is minimal but the mi ture i still to bo since it is simpler and more efficient to pack the bags prior to The temperature at which solidifaction occurs depends on the nitrogen phosphorus potassium ratios of the tion and condition is best observed during the Alternatively according to the invention the method includes the steps of mixing urea and phosphoric acid to form a slurry of urea in phosphoric agitating the adding one or more potassium salts and optionally adding one or more ammonium salts or a mixture of the potassium and ammonium salts to the slurry while agitating and allowing the slurry to cool and set to form a In this form of the invention the mixing of the urea and the phosphoric acid is preferably carried out at temperature not exceeding Preferably the slurry of the i phosphoric acid is stirred for a short approximately one before adding the salts mixture of the bo while the sa to agitate the mi and ensure this form of the invention the slurry is preferably packed into bags immediately after the addition of the salts or the mixture of the After the addition of these salts an exothermic reaction takes place and setting of the slurry to form solid takes place in the It should be added hero that where there is an in the o K ra the of e continued to the exothermic before Also to the invention the dissolving urea in phosphoric acid to form a solution of a c acid cooling adduct to a temperature not exceeding while agitating the adduct adding at least one potassium salt to the adduct and agitating the In this form of the invention the resulting composition may he bagged immediately or stockpiled in bulk and later since it According to another form of the invention the method includes the steps of dissolving urea in phosphoric acid to a solution of a urea phosphoric adding a mixture of potassium salts and ammonium salts urea to the solution while agitating the adding a quantity of phosphoric while the is allowing t e slurry ob to cool j to a d In s of the invention the solution phosphoric acid adduct agitated addition of the potassium salt and the ammonium salts the during the addition of the further quanti of phosphoric Further according to this of the invention where an ammonium salt is added to the mixture the end product is g o where an ammonium is not added the end product is Accordingly where composition i s it be and or but the hygroscopic material should bo to prevent moisture the With this method the quantity of phosphoric acid used initially may be sufficient to dissolve the urea and the balance of the total amount of phosphoric acid to be used is added the addition of the In a preferred embodiment of this method the quantity of phosphoric acid used to the urea initially comprises of the total amount to be and the further quantity of the phosphoric acid added after the addition of the salts comprises the remaining In yet a further embodiment of the invention the method preferably includes the steps of dissolving urea in phosphoric acid to form a solution of a urea phosphoric acid adding the solution to a mixture of one or more potassium salts and one or more ammonium salts while the it to form a particulate this of the invention the resulting solid particulate product is usuall scopic and hence packaging into bags is not essential and furthermore once a bag is opened the entire contents do not have to be completely or the bag In the form of the invention where the urea is phosphoric acid to form a solution of a urea stop is pre out t a within the range to The range is from to The urea for use in carrying out t s method is or spray urea in pill o crystalline The bo wot process thermal process or the acid strength being in the range 0 to The preferred range of acid strength is 21 to The potassium salt or salts to be added to the mixture of urea and phosphoric acid may be selected from nitrate or chloride and should be reasonably so as to avaoid the possible formation of The ammonium salt or salts to bo added to the mixture urea and phosphoric acid may be selected om or nitrate and should pre y also be reasonably pure This invention is also directed at the product of the method described tables of the various formulations of the compositions are with this by way of The various fo of the mixtures are named according to the ratio between P and K that they for example 2 8 contains and K in the 2 to 3 to with a total plant percentage of The denotes the K is present in the number of of the according o the These are given by way of example and the invention is not limited to the particular or of 3 1 5 Dissolve 298 kg Urea in 180 kg phosphoric acid 2 while heating and agitating the Normally the urea starts to dissolve rapidly once the temperature of the reaches and the solution is generally the time the temperature reaches The resulting phosphoric acid adduct is then cooled to and agitated during the cooling Add 522 kg to the urea phosphoric acid adduct and mix and agitate while cooling further to a maximum of the temperature of the is or below and when y is such that settling out is minimal but the mixture it is packed into The bags should be sealed immediately they are filled since material is the method according to this it is possible manufacture soluble fertilizer compositions in solid form are suitable for food with the P 2 These express elemental relative to the total mass of the Λ table of whicli be manufactured according to this method of the invention is Urea 1 Urea L to urea suitable as a foliar spray and containing a of Manufacture 2 4 Cool kg of phosphoric containing P temperature not exceeding Mix urea the cooled acid for a period of approximately one minute at which stage very little urea is dissolved in the Mix kg and add these salts to the urea phosphoric acid Stir while adding ensure thorough Immediately after adding the salts the mixture must EXAMPLE of 2 4 Dissolve kg urea in 480 kg phosphoric containing P heating and agitating the the urea ata to rapidly once the temperature o the mixture reaches and the solution is generally complete the time the temperature reaches urea phosphoric acid adduct is then cooled to a temperature not and agitated during this cooling Then mix 364 with urea acid adduct and agitate to ensure thorough and T e resulting mixture may bagged immediately or stockpiled in and bagged later since it is the method examples 2 and it is possible to manufacture water soluble fertilizer compositions in solid form are suitable for plant food with the following NFK N 6 7 These values express elemental mass as a percentage relative to the total mass of the A table of formulations which may be manufactured according to this method of the invention is given FORMULAE 0 of 3 2 1 213 in 223 acid while heating and agitating the Normally the urea starts to dissolve rapidly once the temperature the mixture reaches and the solution is generally complete the time the temperature reaches Separately mix kg potassium chloride and 189 k ammonium nitrate and mix these dry ingredients with the urea phosphoric acid adduct and at the same time agitate and cool the Add the balance of the phosphoric acid 223 kg in the range of of the total amount while continuing to agitate the The mixture may bagged after the addition of the further quantity of phosphoric acid or in bulk and bagged at a later With the method according to this example it is possible to manufacture water soluble mixed fertilizer compositions in solid form which are suitable for plant food with the following v 1 These values express elemental mass as a percentage relative to the total mass of the Λ table of formulations which may manufactured according to this method of the invention is given 3 Urea K2SO Manufacture of 3 1 Dissolve 83 in 193 phosphoric containing P while heating and agitating the Normally the urea starts to dissolve rapidly once the temperature roaches and the solution is generally complete the the Separately mix potassium sulphate 262 kg ammonium nitrate and add the urea phosphoric acid to the solid ingredients and at the same time agitate and cool the The mixture may immediatel or in and bagged at a later It should be noted here that the rate addition of the urea phosphoric acid adduct and the degree of cooling will determine the particle size of the final The lower the rate of addition of the urea phosphoric acid adduct and the lower the cooling the smaller the particles Wi h the method according to this example it is to manufacture water soluble mixed fertilizer compositions in form are the following PK 5 j P 3 1 values express elemental mass as a percentage relative to the total mass of the Λ of ons which may manufactured according to this method of the invention is given FORMULAE Urea Urea KCt K2SO Fertilizers of the type described are particularly suitable for use in and drip irrigation systems in that they are completely water Furthermore a solution in water has a of between and therefore not very corrosive but may assist in impurities as deposits of which may have accumulated in the spraying In this way the tubes of the spraying equipment and the micro irrigation system arc prevented from being choked and therefore the systems run more It is a feature of fertilizers made in accordance the invention that they include urea phosphates as such in the end This is not a feature of other of It will be appreciated that certain variations in detail exist without materially departing from the scope of the invention as herein In this way part of the nitrogen can be added to the mixture by means of adding nitrate or ammonium sulphate to the trace elements may or may not be added to the mixture as phosphates and phosphates may be added without significantly altering the pH range of a solution in and the like variations are envisaged as falling within the ambit of this insufficientOCRQuality

Claims (1)

1. 46276/2 I M S A method of manufacturing a water soluble mixed fertilizer composition comprising urea-phosphoric add adduct and a potassium salt Including the steps of adding urea to phosphoric acid, adding at least one potassium salt to the resultant mixture and agitating the mixture. A method as claimed In Claim 1 Including the steps of dissolving urea 1n phosphoric add to form a solution of urea phosphoric acid adduct, adding one or more potassium salts to the solution while agitating the solution, cooling the mixture thus formed to a temperature at which undissolved salts will not settle out and allowing the cooled mixture to solidify. A method as claimed In Claim 2 in which the step of dissolving the urea 1n the phosphoric acid 1s carried out at a temperature within the range 68°C to 90°C. A method as claimed In Claim 2 or Claim 3 1n which the solution of urea phosphoric acid adduct Is agitated vigorously during the step of mixing the salts into the solution. A method as claimed In any one of Claims 2 to 4 In which the mixture Is stirred and cooled to a maximum of 43°C until the viscosity thereof Is such that settling out 1s minimal but the mixture is still thin enough to be pourable. 6. A method au claimed in claim 5 in which the cooled : mixture is packed into bags when settling out is minimal but while the mixture is still pourable. 7. A method as claimed in claim 6 in which the bags. are sealed immediately they are filled to prevent absorption of moisture from the atmosphere. i 8. A method as claimed in any one of claims 2 to ' in ' which the constituents of the mixture are chosen so that the final product contains between 13 and 42% nitrogen, between' 2 and 0% phosphorus and between 2 and 28% potassium these values being elemental, mass as a percentage relative to the total mass of the composition. 9. A method as claimed in claim 1 including the steps of mixi g urea and phosphoric acid to form a slurry of rVsa ; ; in phonphoric neid, ag:i a ing the s!l u r , adding one or ' more; pot0.ssiurn salts and optionally adding one or more ammonium salts or a mixture of the potassium and ammonium salts to the slurry and agitating the mixture. 10. A method as claimed in claim. in which the mixing of the urea and the phosphoric acid is carried out at a tempex- ure not exceeding 20°C. 11. A method as claimed in claim 9 or claim 10 in which the alurry ' of tho urea in. phos horic acid is stirred fox1 , a short period, 'before adding the salts or the mixture of ' the salts and stirring is continued while adding the salts.. 12. Λ method as claimed in any one of claims 9, 10 or 11 ixx which the mixture is packed into bags immediately after the addition of the salts or the mixture of the salts. J. A method as claimed in claim 1 including the steps of dissolving urea in phosphoric acid to form a solution of a urea phosphoric acid adduc , cooling the adduct to a temperature not exceeding 40°C while agitating the adduct, adding at least one potassium salt to the adduct and agitating the mixture. 14. A method as claimed in claim 5 in which the step o d:iiaso!l np; tho viroa in the- phosphoric acid ia curried out at a temperature within the range 68°C to 90UC. 15. A method, as claimed in claim 14 in which the solution of urea p osphoric acid adduct is agitated vigorously,^ during tho stop of mixing' l;hc salts in o the solution. 10. A method as e'l aimed in any one of claims 9 to 15 in which tho constituents of the mixture are chosen so that the final product contains between 4 and 10% nitrogen, between 6 and 15% phosphorus and between 7 ^nd 2.8% potassium, these values being elemental mass as a percentage relative to the total mass of the composition. 1 . A method as claimed in claim 1 including Hie steps of dissolving urea in phosphoric acid to form a soluUion of · a. urea phosp oric c:i d adduc , adding a. mixture of po tassium salts and ammonium salts and/or urea to the solution while . ; agitating the solution, adding a further quantity of phosphoric acid while the agitation is continued, and ' allowing the mixture obtained to cool and set to form a solid. 18. A method as claimed in claim 17 in which the step of dissolving the urea in the phosphoric acid is carried . out at a temperature within the range 68°C to 90°C. . A method as claimed in claim 18 in which the solution of urea phosphoric acid adduct is agitated vigorously during the stop o mixing tho salts into the solution. 20. A method as claimed in any one of claims 7 to 19 in .which the quantity of -phosphoric acid used initially is sufficient to dissolve all the urea and the "balance &f the total amount of phosphoric acid to he used is added after the addition of the salts. 21 . Λ method as claimed in claim 20 in which the quantity of phosphoric acid used to dissolve the urea intitially comprises approximately 50 of the total amount to be used and the further quantity of the phosphoric acid added after the addition of the salts comprises the remaining 22. Λ method a;-..ola:i mod -in- any one of claims 17 to 21 .in which the constituents of the mixture arc chosen ao that the final product contains between 5 and 50% nitrogen. · ojf a urea phosphoric acid adduct, adding the solution to ε mixture of one or more potassium salts and one or rnoi^e ammonium salts and/or urea, agitating the mixture and cboling the mixture to form a solid particulate Iproduct. 2†*-. A method as claimed in claim 23 in which the step bf dissolving the urea a.n the phosphoric acid is 'carried out at a temperature within the range 68°C to 90 °0. 25· A method as claimed in claim 23 or claim 24- in which the mixture is agitated vigorously during the s1;-Dp of ! ■- ■ ί · mixing the solution of urea- phosphoric acid adduct into the salts. I sulphate, potassium nitrate and. potassium chloride, the adduct. having been solidified in the presence of the potassium salt. 28. A fertilizer composition as claimed in claim 27 wherein the composition includes at least one ammonium..' salt selected from the class comprising ammonium nitrate and ammonium sulphate. 29· A fertilizer composition as claimed in either claim 27 or claim 28 in which the composition contains between 5 and 2% nitrogen, between 2 and 15 phosphorus and "between 1 and 58% potassium. 30. A solid water soluble mixed fertilizer composition- comprising a intimate solid mixture of urea' phosphoric acid, free phosphoric acid and a potassium salt selected from the class comprising potassium sulphate, potassium nitrate aud potassium chloride the urea phosphoric acid and free phosphoric acid having been solidified in the presence of the potassium salt. 3 . A fertilizer composition as claimed in claim 30 wherein the composition includes at least one ammonium salt selected from the class comprising ammonium nitrate and ammonium sulphate. . . 32. A fertilizer composition as claimed in either claim JO or 31 n v/hich the composition cuti ulna between and. 10% nitrogen, between 6 and 5 phosphorus and between 7 and 28% potassium. ' . 33 · Λ iator soluble mixed fertilizer composition prepared according to the method claimed in any one of claims 1 to .8 which contains "between 13 and 42% nitrogen, between 2 and 10% phosphorus and between 2 and 20% potassium. 34. A water soluble mixed fertilizer composition prepared according to the method claimed in any one of claims , o 9 to 16 which contains between and 10% ' nitrogen, between 6 and 5 phosphorus and between 7 and 28% potassium. 35 · A water soluble mixed fertilizer composition prepared according to the method claimed in any one of claims , or 17 to 22 which contains between 5 and 30% nitrogen, between 3 and 1,5% phosphorus and between 1 and 38% potassium. 36. A water soluble mixed fertilizer composition prepared according to the method claimed in any one of claims 1, br 23 to 2S which contains between 5 and 30% nitrogen, between 3 and 5% phosphorus and etween 1 and potassium. 37. A method of manu acturing a water soluble mixed fertilizer composition in solid. form substantially as herein described with reference to the accompanying examples. , 38. A fertilizer composition substantially as herein" described with reference to the accompanying examples. 39. A fertilizer composition manufactured according to the method claimed in any one of claims 1 to 26 or 37 · 40. A method according to Claim 1 , In which the product 1s substantially 100% soluble 1n water. 41 . A method according to Claim 1 , 1n which the pH of the product In aqueous solution Is between 1 .2 and 2.0. , 42. A method according to Claim 2, In which the product 1s substantial ly 100% soluble 1n water. 43. A method according to Claim 2, 1n which the pH of the product In aqueous solution Is between 1 .2 and 2,0. 44. A method according to Claim 9, In which the product 1s substantially 100% soluble 1n water. 45. A method according to Claim 9, In which the pH of the product 1n aqueous solution Is between 1 .2 and 2.0. 46. A method according to Claim 17, 1n which the product Is substantial ly 100% soluble 1n water. 47. A method according to Claim 17, 1n which the pH of the product In aqueous solution 1s between 1 .2 and 2.0. 48. A method according to Claim 22, In which the product 1s substantially 100% soluble 1n water. 49. A method according to Claim 22, In which the pH of the product 1n aqueous solution 1s between 1 .2 and 2.0. 50. A method according to Claim 26, 1n which the product 1s substantially 100% soluble 1n water. 51. A method according to Claim 26 , 1n which the pH of the product 1n aqueous solution Is between 1.2 and 2.0. 52. A fertil izer composition as claimed In Claim 29, 1n which the product 1s substantial ly 100% soluble 1n water. 53. A fertilizer composition as claimed In Claim 29, 1n which the pH of the product In aqueous solution 1s between 1 .2 and 2.0. 4 - 25 - 54. A fertilizer composition as claimed In Claim 32, 1n which the product 1s substantially 100% soluble 1ri water. 55. A fertilizer composition as claimed 1n Claim 32, In which the pH of the product 1n aqueous solution 1s between 1.2 and 2.0. For the Appl icants , Simon Lav e