BRASIL, E. C.

CEKINSKI, E.

COSTA, M. L. da

DANTAS, R. C. R.

FREDERICCI, C.

HUNGRIA, L. C. da

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,QWHUQDWLRQDO6FLHQWL¿F&HQWUHRI)HUWLOL]HUV&,(&Rio de Janeiro, RJ 2014PROCEEDINGS9LQLFLXVGH0HOR%HQLWHV$GLOVRQGH2OLYHLUD-XQLRU3DXOR6HUJLR3DYLQDWR3DXOR&pVDU7HL[HLUD0LOWRQ)HUUHLUD0RUDHV5HJLQD0DULD9LOODV%{DVGH&DPSRV/HLWH5RQDOGR3HUHLUDGH2OLYHLUDEditorsTECHNOLOGICAL INNOVATION FOR A SUSTAINABLE TROPICAL AGRICULTUREOctober 20-24, 2014Rio de Janeiro, RJ - Brazil19517Introduction The use “in natura” of aluminum phosphate (AP) is infeasible agronomically due to its low solu-bility, caused by the high bond strength between phosphate and aluminum in the mineral. Studies show that this kind of phosphate is their increased solubility, when it is subjected to thermal calcina-tion process, favoring breakage of the crystalline structure of the mineral, increasing the phosphorus available to plants. The use of aluminous phosphates from State of Pará, obtained of the mixture with molten slag mass (liquid), removes the energetic restriction on production process of thermophosphate, favor-ing the reduction of the environmental liabilities of the steel companies in the production of pig iron, as well as contributing for the development of agricul-ture in the state of Pará and Amazon, which have high dependence of phosphate fertilizers from other regions of the country. The work aims to develop technology strat-egies to enable the production of a thermophos-phate from the use of slag mixed with aluminum phosphate, in deposits originating from the North-east of Pará.Methods The development of production process of thermophosphate was conducted at the Technology Research Institute of the State of Sao Paulo. The work in experimental scale involved tests of calci-nation, for the use of rock phosphate of aluminum originating in the Northeast Para, in mixtures of dif-ferent ratios of masses with molten slag, to obtain thermophosphates that were evaluated in terms of WKHLU¿QDOFRQWHQWRI32O5. Treatments involving mixing of different SURSRUWLRQVRIPDVVPDVVRIUDZPDWHULDOWRGH¿QHof relations that contain levels more acceptable of P2O5 LQ GHVLUDEOH WHUPV RI VROXELOLW\ RI ¿QDO SURG-ucts. The aluminum phosphate rock was initially as-sessed for total phosphorus content of the sample and samples with content of P2O5 total suitable, in order to allow acceptable minimum levels of ther-mophosphates produced, since after the mixture there is reduction of initial levels of phosphorus in different combinations of the mass.  For the tests of calcination, in bench scale, combinations of mass of raw materials were es-tablished. To compose the AP mixtures, samples of blast furnace slag were used and subjected to different calcination temperatures. The products obtained of calcination tests were evaluated on the basis of the contents of P2O5XVLQJWKHRI¿FLDOmethod of the Ministry of Agriculture of Brazil.Results and discussion Based on the composition of the raw mate-rial, the AP had appropriate content of P2O5 to al-low the mixture of mass with slag, for the obtaining of thermophosphate. The phosphate also showed high levels of aluminum oxide, which is not avail-able for uptake by plants and thus without the pos-sibility of damaging their growth. The slag of the blast furnace is the largest portion of the total waste generated in the steel industry, being obtained by WKHUHDFWLRQRIÀX[DQGLPSXULWLHVRILURQRUHZKLFKresults in high levels of oxides of silicon (SiO2), alu-minum (Al2O3), iron (Fe2O3) and calcium (CaO). The slag composition varies according to the chemi-cal composition of the raw material (iron ore, coal, limestone) used in the manufacturing process of pig iron. Considering the contents of P2O5 in ther-mophosphates obtained by combining masses of AP and slag, in general, the solubility of ther-THERMOPHOSPHATES OBTAINED OF THE COMBINATION OF ALUMINUM PHOSPHATE AND SLAGEDILSON CARVALHO BRASIL(1)()5$,0&(.,16.,(2,5), CATIA FREDERICCI(2), MARCONDES LIMA DA COSTA(3), LETÍCIA CUNHA DA HUNGRIA(4), RÚBIA CARLA RIBEIRO DANTAS(1) (1) Brazilian Enterprise for Agricultural Research (Embrapa) Oriental Amazon, Travessa Enéas Pinheiro, n/n, Belém-PA, 66095-%5$=,/HGLOVRQEUDVLO#HPEUDSDEU(2) Technological Research Institute of São Paulo, Av. Prof. Almeida Prado 532 Cid. 8QLYHUVLWiULD±%XWDQWm6mR3DXOR63%5$=,/(3) Federal University of Pará, Centre of Geosciences, Department of *HRFKHPLVWU\DQG3HWURORJ\$Y$XJXVWR&RUUHD%HOpP3$%5$6,/ (4) Agronomy, Universidade Federal Rural da $PD]{QLD$Y3UHVLGHQWH7DQFUHGR1HYHV%HOpP3$%5$=,/(5) Maua Technological Institute, Praça Maua, 1 – Sao Caetano do Sul, SP, 05508-901, 09580 900 BRAZILPosters | Section 5 | Fertilizers and environmental impacts16th World Fertilizer Congress of CIEC196mophosphates increased as there was an increase in temperature, in differents combinations of alu-minum phosphate and slag. The calcination promoted reduction of the total levels of P2O5 in AP in the temperatures used. The low water solubility of thermophosphates indi-cates the reduced availability of phosphorus ferti-lizer for plants. When the extracting solution of cit-ric acid 2% was used, there was an inverse effect on the P2O5 levels, observing an increase in the solubility of thermophosphates with the increase of temperature. In this solution, the variation in the concentration of P2O5 was about 8%.  Among the thermophosphates obtained, some combinations of AP and slag showed total levels of P2O5 above of the values minimum re-quirements, established by Brazilian legislation. Conclusions The total content of P2O5 in thermophos-phates produced, ranged within different combina-tions of aluminum phosphate and slag. The solubili-ty of thermophosphates increased with the increase of temperature. Some combinations of AP and slag showed total levels of P2O5 within the minimum re-quirements established by Brazilian legislation..H\ZRUGV)HUWLOL]HUSKRVSKRUXVVROXELOLW\Financial support: FAPESPA/VALE

Thermophosphates obtained of the combination of aluminum phosphate and slag.

http://www.alice.cnptia.embrapa.br/alice/bitstream/doc/999279/1/CPATUp.195196.pdf

Thermophosphates obtained of the combination of aluminum phosphate and slag.

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