Calcium phosphate granules were produced through the calcination of three hydroxyapatites (HAs) at 1150 degrees C: nearly-stoichiometric (NS-HA), calcium-deficient (CD-HA), and carbonated (Carb-HA). The characterization using scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier-transformed infrared spectroscopy (FT-IR) showed that those granules exhibit strong differences in chemical composition, surface texture, and dissolution behavior. Sample dissolution in a simulated body fluid (SBF) and precipitation of a calcium phosphate layer on the granule surface were followed up for 7 days by chemical analysis of calcium content in SBF. After 80-min reaction, precipitation of new calcium phosphate phases predominates over the dissolution of original granules. Comparison between SEM images and XRD/FT-IR analysis revealed that the composition of the calcium phosphate layer and its precipitation rate depend on the HA composition and its heat treatment. Calcined carbonated apatite induces the precipitation of an octacalcium phosphate (OPC) layer, whereas a carbonated apatite layer is formed from calcined-deficient HA. The calcined nearly-stoichiometric HA exhibits low efficiency in producing carbonated apatite layer.

Most manganese used in the world is consumed as ferroalloys by the steelmaking industry. Submerged arc electric furnace smelting using the manganese-rich slag method is widely used to produce ferromanganese. This process has been modelled using the HSC computational thermodynamics package. It was assumed that higher manganese and iron oxides are reduced to MnO and FeO before entering the zone where molten slag and alloy form and equilibrate. The model predictions were compared to data from Thermit Alloys (P) Limited, an Indian ferroalloy smelter, and the agreement was found to be good. It was then used to examine the affects of changing the amount of carbon reductant and temperature on several performance indicators. The results of this modelling are discussed and it is concluded that the model is useful as an aid to understanding ferromanganese smelting.CO CO2 = 1 whereas Fe 3 O 4 reduction to FeO requires either carbon or a gas mixture with a higher CO(g)

This work involves the processing of bovine bone for use as biofilter collector of heavy metals in water. Before processing, it was necessary to clean the bone selected for removing the organic material adhered thereto. Drying was done in weathered during 18 days. Then the bones were calcined at a constant temperature of 750°C for 6 hour. The bone grinding was performed by means of an analytical mill in order to obtain a finer grain size. Once processed, the bovine bone powder was characterized by X-ray diffraction and fluorescence analyses. The results showed that the powder phase is less crystalline hydroxyapatite, when compared to highly crystalline synthetic hydroxyapatite, which favors the sorption capacity of lead by bovine bone.

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Raw materials and products environment friendly has led many authors to develop the area of bio-construction, especially in civil construction, using alternative materials to obtain new achievements. PET (Polyethylene terephthalate) bottles, widely used worldwide, have made it possible to produce very ambitious technological products for their energy and economic efficiency. This study is based on the application of discarded PET bottles for application in ecological building bricks. For this, samples with different PET percent were prepared. The samples were prepared in triplicate.These samples were subjected to tests to verify the optimum setting time/PET ratio.The tests were performed according to international standards and compared to the values of conventional bricks.