MINERAIS CONTAMINANTES DO CAULIM DA MINA IPIXUNA, NO ESTADO DO PARÁ: CARACTERÍSTICAS E INTERFERÊNCIAS NO BENEFICIAMENTO MINERAL

A mina Ipixuna extrai caulim sedimentar e produz matéria-prima final para a indústria do papel. O minério varia devido a presença de minerais contaminantes. Whiteness, yellowness e composição química são parâmetros importantes no processamento mineral. Visualmente, minério com cor vermelha ou amarela é descartado, e com cor clara é aproveitado. Nesta pesquisa, as análises com espectrofotometria, estereomicroscopia e mineralogia com amostras de minério mostraram que a mineralogia contaminante é um indicador importante na tomada de decisão sobre o beneficiamento. Verificou-se que blocos com cor amarela e com alto teor de ferro, podem gerar produto final com qualidade para o papel, quando o principal mineral contaminante é a goethita, removida na separação magnética e branqueamento no químico

FILTRO ANAERÓBIO: USO DE RESÍDUOS DE CONSTRUÇÃO COMO MATERIAL SUPORTE.

O trabalho avalia o desempenho de resíduos da construção civil como cerâmica vermelha e cimentícios (argamassa) para o enchimento de filtro anaeróbio. A pesquisa foi realizada em escala de laboratório utilizando filtros ascendentes com capacidade de 730 ml. Os materiais suporte testados foram os seguintes: brita (material padrão), resíduo de cerâmica vermelha, e este misturado com material cimentício. A água a ser tratada foi coletada na etapa intermediária de uma estação de tratamento. Os filtros foram alimentados de forma contínua e por gravidade, com a vazão de alimentação controlada através do gotejamento. Os materiais empregados foram caracterizados quanto à granulometria, absorção de água e detenção hidráulica. A eficiência de filtragem dos materiais foi avaliada mediante parâmetro de DQO (demanda química de oxigênio). Os resultados mostraram eficiências compatíveis e pouco superiores à da brita. A utilização desses resíduos justifica-se principalmente pela facilidade, disponibilidade e quantidade e valor em relação à brita. Palavras-chave: filtro anaeróbio; material suporte; resíduo de construção. ABSTRACT Anaerobic treatment: use with filter of recycle material from construction. The work, proposes to evaluate the accomplishment of residues generated by civil construction, such as: ceramics and cement, as a support material of biofilm in the anaerobe filtration. The research is utilizing models of anaerobe filters with a capacity of 730ml. In one of the filters will be used a pattern material (mineral rock crunching) that will serve as a comparative element on the efficiency of the other filters. The filters are fed in a continuous way and by gravity. The materials used were characterized: size and water absorption and hydraulic detention. The efficiency of the materials will be measured through the variability of the parameters: CDO (Chemical demand of oxygen). The utilization of these residuals is supported mostly by the easiness, availability, quantity and quality related to the aggregate of rock. Key words: anaerobe filters, support material of biofilm, civil constructio

Rocha basáltica amigdaloide triturada e seus efeitos na produção de tomate

Introduction: Sustainable agriculture plays an important role in agricultural productivity, in which it seeks to reduce dependence on conventional synthetic fertilizers (imported from Europe) and promote the use of alternative, low-cost and environmentally friendly sources. Objetive: An experiment was carried out in the municipality of Santa Maria, Rio Grande do Sul, Brazil, with the objective of evaluating the efficiency and agronomic viability of using a mineral product (amygdaloid basalt powder) as an agricultural input on tomato productivity Solanum lycopersicum L. Methodology: The experimental design used was randomized blocks with six treatments and four replications, at doses 0 (treatment 1 - control), 1.0-t ha–1 of rock dust (treatment 2), 2.5-t ha–1 of rock dust (treatment 3), 3.5-t ha–1 of rock dust (treatment 4), 4.5-t ha–1 of rock dust (treatment 5), and recommended fertilization for tomato 5-20-20 NPK (treatment 6 - standard). Results: The treatments were applied in December 2018 and the transplant took place in February 2019. According to the conditions under which the experiment was submitted and analyzing the results obtained, it can be inferred that the application of 1.0-t ha–1 of amygdaloidal basalt in the soil increased parameters such as root length, stem diameter, green and dry mass of shoots and roots, number of flowers/plants, number of fruits/plant and productivity in tomato Solanum lycopersicum L. Conclusions: It is a viable, sustainable, and low-cost strategy that contributes to the achievement of the Sustainable Development Goal (SDG 2) and can be replicated in Brazil and worldwide.Introducción: La agricultura sostenible juega un papel importante en la productividad agrícola, en la que se busca reducir la dependencia de los fertilizantes sintéticos convencionales (importados de Europa) y promover el uso de fuentes alternativas, de bajo costo y amigables con el medio ambiente. Objetivo: Se realizó un experimento en el municipio de Santa Maria, Rio Grande do Sul, Brasil, con el objetivo de evaluar la eficiencia y viabilidad agronómica del uso de un producto mineral (polvo de basalto amigdalino) como insumo agrícola sobre la productividad del tomate Solanum lycopersicum L. Metodología: El diseño experimental utilizado fue bloques al azar con seis tratamientos y cuatro repeticiones, en las dosis 0 (tratamiento 1 - control), 1.0-t ha–1 de polvo de roca (tratamiento 2), 2.5-t ha–1 de polvo de roca (tratamiento 3), 3.5-t ha–1 de polvo de roca (tratamiento 4), 4.5-t ha–1 de polvo de roca (tratamiento 5), y fertilización recomendada para tomate 5-20-20 NPK (tratamiento 6 - estándar). Resultados: Los tratamientos se aplicaron en diciembre de 2018 y el trasplante se realizó en febrero de 2019. De acuerdo con las condiciones en las que se sometió el experimento y analizando los resultados obtenidos, se puede afirmar que la aplicación de 1-t ha–1 de basalto amigdaloidal en el suelo incrementó parámetros como longitud de raíz, diámetro de tallo, masa verde y seca de brotes y raíces, número de flores/plantas, número de frutos/planta y productividad en tomate Solanum lycopersicum L. Conclusiones: Es una estrategia viable, sostenible y de bajo costo que contribuye a la consecución del Objetivo de Desarrollo Sostenible (ODS 2) y puede ser replicada en Brasil y en todo el mundo.Introdução: A agricultura sustentável tem papel relevante na produtividade agrícola, na qual busca reduzir a dependência de fertilizantes sintéticos convencionais (importados da Europa) e promover o uso de fontes alternativas, de baixo custo e ambientalmente amigáveis. Objeto: Foi realizado um experimento no município de Santa Maria, Rio Grande do Sul, Brasil para avaliar a eficiência e a viabilidade agronômica da utilização de um produto mineral (pó de basalto amigdalóide) como insumo agrícola na produtividade do tomateiro Solanum lycopersicum L. Metodologia: O delineamento experimental utilizado foi o de blocos casualizados com seis tratamentos e quatro repetições, nas doses 0 (tratamento 1 - controle), 1.0-t ha–1 de pó de rocha (tratamento 2), 2.5-t ha–1 de pó de rocha (tratamento 3), 3.5-t ha–1 de pó de rocha (tratamento 4), 4.5-t ha–1 de pó de rocha (tratamento 5), e fertilização recomendada para o tomate 5-20-20 NPK (tratamento 6 - padrão). Resultado: Os tratamentos foram aplicados em dezembro de 2018 e o transplante ocorreu em fevereiro de 2019. De acordo com as condições em que foi submetido o experimento e analisando os resultados obtidos, pode-se inferir que a aplicação de 1.0-t ha–1 de pó de basalto amigdaloidal no solo aumentou parâmetros como comprimento da raiz, diâmetro do caule, massa verde e seca da parte aérea e da raiz, número de flores/plantas, número de frutos/planta e produtividade em tomateiro Solanum lycopersicum L. Conclusões: É uma estratégia viável, sustentável e de baixo custo que contribui para o cumprimento do Objetivo de Desenvolvimento Sustentável (ODS 2) e pode ser replicável no Brasil e no mundo

Sustainable release of macronutrients to black oat and maize crops from organically-altered dacite rock powder

By-products from the dairy industry and mining activities represent a great environmental overload, which justify research for value-added reuse of these by-products (dairy sludge and dacite rock powder). Dairy sludge is generated at a rate of about 0.2–10 l per liter of processed milk, and dacite powder, from rock mining extraction and processing, is generated for about 52,400 m3 per year in Nova Prata city, Southern Brazil. For both by-products, the compositions of calcium (Ca), magnesium (Mg), potassium (K) and phosphorous (P), arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), and lead (Pb) were determined by using appropriate analytical techniques. A greenhouse experiment was conducted to determine release of macronutrients, such as Ca, K, Mg, and P, from by-products to support black oat (Avena strigosa) and maize nutrition. Twelve by-products doses were blended with a typic Hapludox soil and were applied to pots with five replications each. Black oat (first cultivation) and, sequentially, maize (second cultivation) were cultivated for 70 days each. Ameliorations in soil chemical attributes, leaf dry matter yield, and plant nutritional status were evaluated at the end of each cultivation. There was a significant (p < 0.05) increase in all parameters evaluated in a dose of 7251 kg ha−1 of dacite rock powder and 20,594 kg ha−1 of dairy sludge. Compared to the control treatments, both crops grew well better on all mixtures. The presence of potentially toxic elements in both by-products was irrelevant, indicating that effective blending of dacite rock powder along with dairy sludge could be a potential source of Ca, K, Mg, and P in agriculture without posing a risk of contamination to the environment

Application of Andesite Rock as a Clean Source of Fertilizer for Eucalyptus Crop: Evidence of Sustainability

Global demineralization of agricultural soils due to unsustainable use of highly soluble fertilizers and intensive exploitation is an issue of increasing concern. Methods of remineralization include the application of volcanic rock by-product, such as vesicular andesite on mineral-deficient fields. The present work analyzed the petrography, mineralogy, and chemistry of volcanic rock by-product (vesicular andesite rock), as well as on-field experiment with eucalyptus. The petrographic description was performed on a polished thin section by optical microscopy. The mineralogical phases were identified with X-ray diffraction. The by-product chemical composition was determined by X-ray fluorescence and inductively coupled plasma mass spectrometry for potentially toxic elements. Additional chemical compositions were analyzed using a scanning electron microscope equipped with a dispersive X-ray detector. A nine-month field experiment was carried out to evaluate the agronomic performance of Eucalyptus saligna Smith cultivated in an Ultisol. Four different doses (treatment T1 = control, treatment T2 = nitrogen, phosphorous, and potassium fertilizer 100 %, treatment T3 = by-product 100 %, and treatment T4 = by-product 50 % and nitrogen, phosphorous and potassium fertilizer 50 %), were applied on soil. Responses to treatments were evaluated from height and diameter at breast height at three, six, and nine months after eucalyptus planting. The total phosphorous and potassium content in soil was measured at three and six months after eucalyptus planting. The results showed that the by-product is composed of plagioclase, potassium feldspar, zeolite, smectite, and opaque minerals with apatite as an accessory mineral. The primary oxides found in by-product via X-ray fluorescence were silicon, aluminum, iron, calcium, sodium and with lower concentration, the potassium and phosphorus. In all evaluated parameters, it was verified that T2 and T4 treatments significantly enhanced the available soil phosphorous, and the eucalyptus height, with maximum gains (79 % and 62 % of phosphorous, and 20 % and 23 % of height) at nine months after eucalyptus plantation. The maximum gains of eucalyptus diameter at breast height were similar (23 % and 24 %) at six months after plantation. Soil available potassium was significantly enhanced in T3, T4 and T2 treatments at nine months after planting, with maximum gains of 71 %, 55 % and 53 %. The work indicated an improvement in the phosphorus and potassium levels in soils, and in eucalyptus crop growth by adding by-product, being a partial nitrogen, phosphorous, and potassium fertilizer substitution strategy. The use of these geological materials is presented as an alternative to increase agricultural productivity and reduce the environmental impacts caused by excessive use of highly soluble fertilizers

Understanding the mobility of potential nutrients in rock mining by-products: An opportunity for more sustainable agriculture and mining

The increase in demand for highly soluble fertilizers brings a global sustainability concern. Alternative sources for traditional fertilization are therefore needed. Rock powder use has been proposed as an alternative approach to soil remineralization. However, research on the agricultural potential of minerals and rocks as alternative sources of nutrients is limited to changes in soil chemical attributes or effects on crop yield. In this work, we report an experimental study addressing the dissolution of two silicate rock-derived powders (andesite and dacite) that were produced during mining activities in Southern Brazil. The rock powders were exposed to Milli-Q water at pH (7.4–8.8) range, in solutions of 0.1 mol L−1 citric acid at pH range 2.1–3.3, and Milli-Q water acidified with 0.5 mol l−1 acetic acid (pH 5–5.8), in a continuous mechanical rotatory shaker at room temperature. Dissolution kinetics were determined as a function of reaction times at 24 to 5760 h, and solution pH. Based on this kinetics, dissolution rates were determined for the individual powders and compared to expected values for aluminosilicates. Based on this comparison, it was shown that the application of andesite and dacite rock-derived powder to replace high soluble fertilizers is feasible due to high dissolution rates of their minerals. The average andesite dissolution rates in Milli-Q water, in citric acid solution, and in Milli-Q water acidified with acetic acid were 2.1 × 10−5, 1.92 × 10−1 and 6.3 × 10−4 mmol cm−2 s−1, respectively for Ca, being 183%, 22.6%, and 69.2% higher than for the dacite rock. This make andesite rock a potential substitute for carbonate-based liming. In contrast, the average dacite dissolution rates in Milli-Q water, in citric acid solution, and in Milli-Q water acidified with acetic acid were 1.05 × 10–5, 7.22 × 10−5, and 3.72 × 10−5 mmol cm−2 s−1, respectively for K, being 72.0%, 61.4%, and 73.6% higher than the andesite rock. This highlights its potential use as a K source for agriculture to replace highly soluble K-fertilizers

Evaluation of the potential of volcanic rock waste from southern Brazil as a natural soil fertilizer

This study was developed to evaluate the chemical and mineralogical properties of acid volcanic rock waste from mining activities by measuring the availability of macronutrients and micronutrients in Milli-Q water, and in acidic solutions to evaluate the potential use of this type of waste as natural soil fertilizers. The sample used in this work was obtained from a company of the mining district of Nova Prata, Rio Grande do Sul State, southern Brazil. Petrographic studies using conventional optical microscopy and scanning electron microscope allowed to define the mineral composition of in powder wastes as being comprised mainly by pyroxene, feldspar, and variable contents of amorphous glass in matrix. The primary oxides detected in the samples by X-ray Fluorescence were calcium oxide, silicon dioxide, aluminium oxide, iron oxide, and with concentration minor potassium oxide, and phosphorus oxide. Several important nutrients were transferred into the acidic solutions, indicating the significant potential and feasibility of these wastes to be effectively used as natural fertilizers. This study is of great relevance to the sector of mining and to agriculture in the region because it can create an alternative disposal treatment for tailings, and improve the environmental sustainability of local farms, thereby avoiding excessive chemical fertilizer consumption