Os minérios de manganês provenientes da mina do Azul são importante matéria-prima na produção de ferro-ligas de manganês. Visando melhorias no beneficiamento e no processo de fabricação destas ligas, foi realizada a caracterização do produto Granulado da unidade do Azul-VALE/Manganês. Foi obtida uma amostra representativa desta mina e realizada análise granulométrica, onde se verificou a ocorrência de 80% das partículas abaixo de 22,6mm e 50% abaixo de 12,5mm. Considerou-se como granulado a fração menor que 37,5mm e maior que 6,3mm, que é a mais abundante neste minério e comumente destinada às usinas de ferro-ligas. A fração entre 37,5mm e 6,3mm foi amostrada e foram realizadas análises termogravimétrica, química dos elementos majoritários e identificadas as fases minerais presentes. A análise térmica (TG-DTA) identificou perda de massa em torno de 300ºC, 500ºC, 700ºC, 900ºC e 1000ºC associadas à decomposição térmica de algumas fases minerais presentes. Os teores de Mn, Fe e SiO2 foram respectivamente, 47,68; 3,59; e 3,16%. O produto Granulado da unidade do Azul é composto majoritariamente pelos minerais de manganês criptomelana [KMn8O16] e pirolusita [MnO2]. Os constituintes minoritários são todorokita [(Na,Ca,K)2Mn6O12 •3-4.5(H2O)], magnetita[Fe3O4] e gibbsita [Al(OH)3] (A pirolusita, a magnetita e a gibbsita foram identificadas por microscopia óptica).

The manganese ores from Azul mine are important raw materials for ferro alloys production. For improvements in the manganese ferro alloys production, Azul's lump ore product was characterized. A representative sample from the mine has been obtained and their particle sizes were classified. The size distribution showed that 80% of particles were below 22.6mm and 50% were below 12.5mm. The particles with sizes between 37.5mm and 6.3mm were named lump ore product. The fraction between 37.5mm and 6.3mm was submitted to chemical and mineralogical characterization. The TGA tests showed weight losses in 300ºC, 500ºC, 700ºC, 900ºC and 1000ºC due, mainly, the high manganese oxides decompositions. The Mn, Fe and SiO2 contents were, respectively, 47.68%; 3.59% and 3.16%. Azul's lump product has cryptomelane[KMn8O16] and pyrolusite[MnO2] as main mineralogical constituents. todorokite[(Na,Ca,K)2Mn6 O12•3-4.5(H2O)], magnetite[Fe3O4] and gibbsite[Al(OH)3] appear as minor constituents (Pyrolusite, magnetite e gibbsite were identified by optical microscopy).

Glycaspis brimblecombei Moore is an Australian native pest of Eucalyptus detected in Brazil in 2003. Since then, it has spread fast and colonized plantations in several states of the country. This study aimed to investigate the influence of cerrado remnants on the abundance and biological control of G. brimblecombei. We placed yellow sticky card traps to capture insects in four plantations of hybrid clones of Eucalyptus urophylla x Eucalyptus grandis ("Urograndis") and four plantations of E. urophylla x Eucalyptus camaldulensis ("Urocam"). Traps were placed in three areas of these plantations: center, border with cerrado and border without cerrado. We also collected leaves from the same clones to estimate psyllid egg and lerp abundance. The abundance of G. brimblecombei was lower in the plantation-cerrado border, and the inverse pattern was observed for microhymenopterans. The leaf abaxial surface showed a higher abundance of eggs and nymphs, probably as a consequence of a lower parasitism rate and mechanical removal by wind and rain. Egg number was higher on Urograndis than in Urocam clones, but the number of psyllid lerps was higher in the latter. Thus, the establishment of first instars is probably a critical event to psyllid infestation, and these differences may be caused by morphological, anatomical and biochemical leaf features of distinct clones. Our results suggest that the maintenance of native vegetation around plantations is a promising management practice to promote the natural biological control of G.brimblecombei, a strategy that would also enhance the preservation of cerrado remnants.

Este estudo foi conduzido com o objetivo de avaliar o desempenho e as características de carcaças de alevinos de tilápia do Nilo (Oreochromis niloticus) submetidos a rações com níveis de inclusão de farinha de vísceras (FV), assim como os coeficientes de digestibilidade aparente (CDA) dos nutrientes deste alimento. Para o experimento de desempenho, foram utilizados 300 alevinos, com peso inicial médio de 0,35 ± 0,01 g, distribuídos em trinta tanques-rede (120 L), instalados em cinco tanques (1000 L). Foram utilizados seis níveis de inclusão de FV nas rações (0,00; 4,00; 8,00; 12,00; 16,00 e 20,00%), em um delineamento experimental, em blocos casualizados com seis tratamentos e cinco repetições. Realizou-se um ensaio de digestibilidade, com rações contendo 0,00 e 20,00% de FV, fornecidas a peixes com peso médio de 47,81 ± 9,97 g. Observou-se aumento linear da porcentagem de ganho de peso e taxas de eficiência protéica e de retenção de nitrogênio, com o aumento nos teores de FV nas rações, e efeito quadrático para conversão alimentar, taxa de retenção de extrato etéreo e porcentagens de proteína bruta e extrato etéreo na carcaça. Em relação à digestibilidade, a ração com 20,00% de FV apresentou menores CDA para a matéria seca, proteína bruta e energia bruta e maiores para extrato etéreo. Entretanto, maiores valores de extrato etéreo e energia digestíveis foram obtidos na ração com 20,00% de FV, embora a proteína digestível tenha sido inferior com 0,00% de FV. Os CDA do extrato etéreo, proteína bruta e energia bruta da farinha de vísceras foram de 70,45; 63,93 e 55,89%, respectivamente. A inclusão de 20,00% de FV na ração promoveu melhor desempenho, porém aumentou o teor de extrato etéreo e reduziu o de proteína bruta na carcaça, ocorrendo, ainda, diminuição dos CDA da matéria seca, proteína e energia bruta das rações.

Performance, carcass characteristics and coefficients of apparent digestibility of Nile tilapia fingerlings (Oreochromis niloticus) fed diets with increasing levels of poultry by-product meal (PM) were evaluated. Three hundred fingerlings with average initial weight of 0.35±0.01 g were placed in thirty 120 L net ponds in five cement 1000 L tanks. Six levels of PM inclusion (0.00, 4.00, 8.00, 12.00, 16.00 and 20.00%) were used in the diets, in an experimental randomized blocks desing with six treatments and three replicates. An experiment of diet digestibility was undertaken with 0.00 and 20.00% PM diets on fish of average weight 47.81±9.97 g. A linear improvement was observed at PM inclusion levels with regard to final weight, percentage of weight gain, protein efficiency rate, nitrogen retention and quadratic effect for food conversion, ether extract retention and percentages of crude protein and carcass ethereal extract. Concerning to the digestibility experiment, the 20.00% PM diet showed lower coefficients of apparent digestibility for dry matter, crude protein, crude energy and higher coefficients for ether extract. However, higher values of digestible ether extract and energy were obtained with 20.00% PM diet, even though digestible protein was lower than the 0.00% PP diet. Apparent digestibility coefficients of the ether extract, crude protein and crude energy of PM for the Nile tilapia were 70.45, 63.93 and 55.89% respectively. Thus, the inclusion of 20.00% PM in diet improved performance, however increased ether extract content and decreased crude protein levels in carcass and dry matter, crude protein and energy digestibility coefficients of the diets.