Low-temperature calcination of “C”-grade phosphate from christmas island

Doak, B. W.; Gallagher, Patrick; Evans, L.; Müller, Franz

doi:10.1080/00288233.1965.10420020

Cited by 43 publications

(23 citation statements)

References 2 publications

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“…Although oflittle agronomic value in the raw state, calcination at 550·C increases the agronomic performance of this material. Calciphos has been evaluated extensively in both the glasshouse and the field in New Zealand (Doak et al 1965;Buchan et al 1970;Muller 1970).…”

Section: Introductionmentioning

confidence: 99%

A glasshouse comparison of 6 phosphate fertilisers

Mackay

Syers

Gregg

1984

New Zealand Journal of Experimental Agriculture

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In a glasshouse experiment the effectiveness of Chatham Rise phosphorite (CRP) as a source of phosphorus (P) for perennial ryegrass and white clover on 6 contrasting soils was compared with single superphosphate, North Carolina phosphate rock (NCPR), Sechura phosphate rock (SPR) from Peru, Tennessee phosphate rock (TPR), and calcined Christmas Island 'C' grade phosphate rock (Calciphos). The 6 P sources are ranked in the following order of effectiveness for ryegrass under glasshouse conditions: superphosphate ~ NCPR ~ SPR > CRP > > Calciphos > > TPR. A marked difference was found in the ability of the 2 plant species to use P from a phosphate rock (PR). SPR was as effective as superphosphate on clover. This was particularly pronounced when the comparison was based upon P uptake data rather than yield data. In fact there was no difference between superphosphate, SPR, and CRP when P uptake by clover was used as the measure of effectiveness. When P uptake by ryegrass was used to assess agronomic performance rather than ryegrass yield data, the reactive PR materials, NCPR, SPR, and CRP were far less effective than superphosphate. The results indicate that both dry matter yield and P uptake data are required to fully evaluate the agronomic effectiveness of PRo Extrapolation of the results of this glasshouse experiment to field situations is discussed.

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Section: Introductionmentioning

confidence: 99%

A glasshouse comparison of 6 phosphate fertilisers

Mackay

Syers

Gregg

1984

New Zealand Journal of Experimental Agriculture

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“…When the crandallite structure is heated to 700°C and above, new crystalline structures can develop, i.e., whitlockite or phosphocristobalite (Gilkes & Palmer, 1979), which were not observed in Figure 2 -X-ray diffractograms for Tapira, Catalão, and Juquiá residues and powder diffraction file data for the minerals crandallite, goethite, kaolinite and quartz. Doak et al (1965), Câmara et al (1984), Guardani (1987), it is possible to suggest that the structural disorganization upon thermal treatment may occur in response to the loss of hydration water, which could provoke collapse of the crystalline structure. The same effect of calcination on mineralogical composition was observed for Tapira and Catalão, that is, original goethite was gradually transformed into hematite following heating, and the crystalline structure of aluminous phosphates of the crandallite group was disorganized at 500°C and higher temperatures.…”

Section: Resultsmentioning

confidence: 99%

“…These aluminous phosphates are unsuitable to be used in the acidulation process, but were once marketed worldwide as P sources for direct application after their thermal treatment (Doak et al, 1965;Mason & Cox, 1969).…”

Section: Introductionmentioning

confidence: 99%

Thermal treatment of aluminous phosphates of the crandallite group and its effect on phosphorus solubility

Francisco

Prochnow²,

Toledo³

et al. 2007

Sci. agric. (Piracicaba, Braz.)

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Optimization in the use of phosphate rocks is important and the residues of fertilizer production in the form of crandallite may be suitable for agronomic use after calcination. With the objective of evaluating the effect of thermal treatment of the aluminous phosphates of the crandallite group as related to solubility, crystalline structure and morphology, samples from the mine residues of three Brazilian phosphate deposits (Tapira-MG, Catalão-GO, and Juquiá-SP) were collected, air-dried, and screened to 100 mesh. Sub samples were thermally treated at 300, 500, 700, and 900°C for 2 hours. Treated and untreated materials were analyzed by X-ray diffraction, scanning electronic microscopy, energy dispersive X-ray spectrometry, and for the total and soluble P contents. The treatment of samples: (i) raised P solubility in neutral ammonium citrate solution, (ii) caused the disorganization of the crystalline structure of crandallite at 500°C and above, and (iii) altered their morphology (cracking and rounding). The increase in P solubility of samples after calcination indicates that the agronomic utilization of these marginal P sources may be of interest since plant growth may be favored due to higher P availability. New studies to evaluate these materials in order to determine their agronomic effectiveness must be carried out to establish adequate conditions that favor their use by plants. Key words: calcination, phosphate fertilizer, phosphate impurities TRATAMENTO TÉRMICO DE FOSFATOS ALUMINOSOS DO GRUPO DA CRANDALLITA E SEU EFEITO NA SOLUBILIDADE DO FÓSFORORESUMO: A otimização do uso de rochas fosfáticas é importante e resíduos da indústria de fertilizantes fosfatados na forma de crandallita poderão ser agronomicamente eficientes após calcinação. Com o objetivo de avaliar o efeito do tratamento térmico em fosfatos aluminosos do tipo crandallita quanto à solubilidade, estrutura cristalina, e morfologia, amostras do rejeito de mineração de três depósitos fosfáticos brasileiros (Tapira-MG, Catalão-GO e Juquiá-SP) foram coletadas, secas ao ar e separadas por peneiramento 100 mesh. Sub-amostras foram submetidas ao tratamento térmico a 300, 500, 700 e 900°C durante 2 horas. Os materiais tratados e não-tratados foram analisados por difratometria de raios X, observados por microscopia eletrônica de varredura e espectrometria por energia dispersiva, e seus teores de fósforo total e solúvel determinados. O tratamento térmico das amostras: (i) elevou, consideravelmente, a solubilidade em CNA dos materiais; (ii) promoveu a desorganização da estrutura cristalina da crandallita a temperaturas de 500°C e superiores; e (iii) causou alterações morfológicas (fraturamento e arredondamento) nas amostras. O aumento na solubilidade das amostras após o tratamento térmico indica que a utilização agronômica destas fontes marginais de P pode ser de interesse, uma vez que o crescimento das plantas pode ser favorecido pela maior disponibilidade de P. Estudos de avaliação desses materiais a fim de determinar sua eficiência agronômica...

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“…Importantly, the decomposition curves can be obtained and mechanism of decomposition of the mineral determined. Generally, the theoretical mass loss of water is 10.46%, and structural disorganization upon thermal treatment may occur in response to the loss of hydration water, which could provoke collapse of the crystalline structure (Doak et al, 1965). The two overlapping mass loss steps at 263 and 280 uC are attributed to the hydroxyl group (Palmer and Frost, 2010).…”

Section: Discussionmentioning

confidence: 99%

Geochemical and mineralogical analysis of Kashmir Cave (SMAST), Buner, Pakistan, and isolation and characterization of bacteria having antibacterial activity

Zada¹,

Naseem²,

Lee³

et al. 2016

JCKS

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Bacterial strains having the ability to inhibit the growth of other bacteria were isolated from soil samples collected from Kashmir Smast (smast is Pushto for cave), Khyber Pakhtunkhwa, Pakistan. The study includes mineralogical and geochemical analyses of soil sample collected from the cave, so as to describe the habitat from which the microorganisms have been isolated. Total bacterial count of the soil sample was 5.25 3 10 4 CFU mL −1. Four bacterial isolates having activity against test organisms Micrococcus luteus, Klebsiella sp., Pseudomonas sp., and Staphylococcus aureus were screened out for further study. Two of the isolates were found to be Gram-positive and the other two Gram-negative. The four isolates showing antibacterial activity were identified as Serratia sp. KC1-MRL, Bacillus licheniformis KC2-MRL, Bacillus sp. KC3-MRL, and Stenotrophomonas sp. KC4-MRL on the basis of 16S rRNA sequence analysis. Although all isolates showed antibacterial activity, only Bacillus licheniformis KC2-MRL was selected for further study due to its large zone of inhibition. Antibacterial activity of B. licheniformis KC2-MRL was optimum when grown in nutrient broth adjusted to pH 5 and after 24 hours of incubation at 35 uC. The extracted antibacterial compound was stable at pH 5-7 and 40 uC when incubated for 1 hour. The strain was found resistant against cefotaxime (ctx). Atomic-absorption analysis of the soil sample collected from the cave showed high concentrations of calcium (332.938 mg kg ) compared to the control soil collected outside the cave. FTIR spectrum of the concentrated protein showed similarity to bacitracin. The antibacterial compound showed activity against both Gram-negative and positive test strains. Mineralogy of Kashmir Smast is diverse and noteworthy. Different geochemical classes identified by X-ray diffraction were nitrates, oxides, phosphates, silicates, and sulfates. Weathered cave limestone contributes notably to the formation of these minerals or compounds. FTIR spectroscopic analysis helped to identify minerals such as quartz, clinochlore, vermiculite, illite, calcite, and biotite.

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Low-temperature calcination of “C”-grade phosphate from christmas island

Cited by 43 publications

References 2 publications

A glasshouse comparison of 6 phosphate fertilisers

A glasshouse comparison of 6 phosphate fertilisers

Thermal treatment of aluminous phosphates of the crandallite group and its effect on phosphorus solubility

Geochemical and mineralogical analysis of Kashmir Cave (SMAST), Buner, Pakistan, and isolation and characterization of bacteria having antibacterial activity

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