Wildor Theodoro Hennies

Logística para agregados (brita e areia) em grandes centros urbanos

One of the human beings basic needs is housing. In Brazil, the basic element for this is concrete, artificial stone, which demands a great amount of aggregates, such as sand and gravel. The sand and rocks are abundant in nature and gravel can be produced at low cost. However, transportation to the area of product utilization can be an incremental factor in the final cost logistics. Both sand and gravel have expressive price variations, which are not necessarily related to mining activities, but to logistic activities, mainly their distribution. Restrictive measures adopted in large urban centers, such as prohibition of hauling trucks in certain areas or during certain hours, alternate license plate end number system (even number plate ending can circulate on even-numbered days and visa versa), and axle-control, generate a need for a larger and more diversified fleet, not to mention more employees.

Fatal Accidents and Rockfalls in Peruvian Underground Mines

Developing countries depend on primary industries such as the mineral industry. Peru is one of the most important mineral producers in the world and political and economic stability have brought great interest in mining in the past 20 tears. In the Peruvian economy, about 6% of Gross Domestic Product (GDP) and over 50% of exports are provided by mineral commodities. The Peruvian mining industry has become aware of the need to improve health and safety of the people involved in the industry. Peruvian regulations on mining health and safety, approved in 2001, are intended to protect human life, promote health and safety and reflect the culture of prevention related to incidents and accidents. A decrease in the number of mining accidents in recent years has been perceived but the mortality rate is still high when compared to traditional mining countries. Official reports state that the fundamental causes for the accidents are related to personal and work factors, as well as human errors. Therefore an accurate identification of causes is required for better safety and health management systems. From 2000 to 2007 there were 433 fatal accidents with 499 fatal victims in Peruvian mining industry and the majority of these accidents were caused by rockfalls in underground excavations. In addition, a study of rockfalls in 2007 has brought information about where (in the mine) these accidents occurred and who were the victims. Human errors, personal factors and non-complying procedures have contributed to these accidents.

Technology Characterization of Organo-Clays Obtained from Bentonites of the State of Paraiba

The organo-clays have important industrial uses between others are: rheological additives for drilling fluids in oil bases, inks, glues, lubricants and cosmetics. At the moment and in a growing way, these materials are considered as important reinforcement fillers in the structuring of nano-composites clays/polymers. They are obtained by the smectite clay reaction with quaternary ammonium salts. In this work an organophillic clay sample prepared by a dry process at the PMT – EPUSP – Metallurgic and Materials Engineering Department of the Polytechnic School at the University of São Paulo, had been characterized basically by techniques of XRD, IR, Thermal Analysis, and by swell capacity of the clays in some oils and organic solvents.

Synthesis and Characterization of Organophilic Clay from Cuban Chiqui Gomez Bentonite

Smectites are clay mineral with a layered structure and nanometric thickness, high specific area and a huge variety of uses. Consisting on stacked layers of about 1nm thickness, including two silica tetrahedral and one octahedral sheet. Properties of natural Smectites can be enhanced by organic modification, due to the substitution of the exchangeable cations in the interlayer area. In fact, the properties of the modified smectite (organophilic clay) are related to its modified chemical composition and structural parameters. The interaction of smectite clays with surfactants has an important interest in the fields of drilling fluids, paints, cosmetic, ceramic industries and others. Recent applications are: remediation of contaminated areas and polymer/clay nanocomposites. The aim of this paper is to obtain organophilic clays using a bentonite from the Chiqui Gómez deposit in Central Cuba. The raw and organophilic clays were analyzed by DRX, SEM, swelling capacity in organic solvents and others.

Applications of Ultra High-Pressure Powder-Abrasive Waterjet

The paper describes the technique developed for applying garnet powder abrasive ultra-high pressure water jet advanced technology (AWJ) to build accurate models of artistic objects. The objects to be modeled have been selected through a cooperative initiative between the University of Sao Paulo and entities of the private sector. The first application was the reproduction of the artistic floor of marble at the St. Marks Basilica, Venice, Italy. The other application was the production of official trophies for a technical awards ceremony for a national symposium that took place in Brazil. The trophies were made in stainless steel, whilst the floor reproduction was made in ceramic tiles. The floor was reproduced from high-definition photography of the original floor. The design concept and the blueprints of the trophies were originally conceived by the symposium organizers. Both models have been built using OMAX® CAD/CAM Software, which controls an AWJ unit installed at the University of São Paulo, where the procedures for building both models have been developed and executed with high success.

Análise de acidentes fatais na mineração: o caso da mineração no Peru

A mineracao e uma das atividades industriais que oferecem maior risco; embora nos ultimos anos tenham-se percebido reducoes na taxa de lesoes e acidentes, o seu numero e grau de severidade ainda sao elevados. As causas fundamentais para as altas taxas de acidentes podem ser atribuidas as condicoes inseguras e os atos inseguros; nesse cenario, a identificacao de problemas de seguranca visando a proposta de solucoes efetivas para gerenciar riscos faz-se necessaria. Por outro lado, a dependencia de paises em desenvolvimento por industrias primarias como a mineracao e evidente. Na economia peruana, aproximadamente, 16 % do PIB e mais de 50 % das exportacoes referem-se a esta industria, destacando sua posicao competitiva na mineracao mundial. Esse artigo analisa os acidentes fatais na mineracao peruana, desde o ano 2000 ate maio de 2008. A fonte de informacao primaria foi o registro de acidentes, disponibilizado pelo Ministerio de Energia e Minas do Peru; identificando-se varios tipos de acidentes com destaque para aqueles provocados por queda de rochas em minas subterrâneas. A maioria das vitimas sao trabalhadores de empresas terceirizadas prestadoras de servicos especializados. Os resultados mostram que a mineracao subterrânea tem maiores riscos do que a de superficie.

Replacement of Carbon Black on Natural Rubber Composites and Nanocomposites — Part 1

Seeking to replace carbon-black as filler of rubber in the production of vulcanized goods, researchers from University of Sao Paulo have studied different materials types as minerals, vegetal or wastes agricultural and industry. Results of rubber composites filled with MA1 a waste of mineral treatment provided by Esper Industries are presented. MA1 was characterized through X-ray diffraction; Thermal analysis; Scanning Electronic Microscopy; and others laboratory methods. The composite and shaped masses were evaluated by these methods plus their mechanical properties such as tensile strength, elongation at break and hardness. Exceptional results were obtained in the mechanical properties evaluated, better than those obtained with the traditional carbon-black. Seeing the kind of material used as filler, it can conclude that the environmental benefit is present, as well as economic development, giving credibility to the use of these alternative material in replacement carbonblack.

Nanoparticles of Carbonaceous Minerals in Vulcanized Rubber Products

The use of vulcanized rubber products is widely spread in the industry and in the society. Tires, shoes, tennis and other are examples of it. Most of the raw materials used in the formulations of vulcanized rubber products come from the synthesis of natural raw materials consuming time and energy and also generating CO2 emissions during the respective transforming processes. The main reinforcing material used in rubber formulations is the carbon-black which is a petroleum derivative obtained by the incomplete burning of the fossil fuel. This paper show some results obtained after replacing all or part of the carbon-black by carbonaceous nanoparticle minerals in rubber formulations.

Tire Rubber Powder/ Rice Husk Ash Polymer Compound

The advantage of the incorporation of tire rubber powder and rice husk ash in the polymer compound is mainly due to the reduction of the products cost, as well as improving the essential properties for a great processing of the material, for example, its flow into a hole of a thin wall mold. The rice husk ash can replaces the carbon black in the new products, contributing with the improvement of the environment and the economy of the society. Main objectives of this work are: enhance the applications of the ashes from the rice husk and the waste from the tire rubber, as well as, study new methods of recycling of polymeric wastes, to incorporate an aggregated value to the recycled materials as well as obtaining compounds or nanocompounds materials.

Contribution to a technological characterization of kaolins from Cuba and Brazil

This paper studies the main well-know technological types of kaolins clays from the Republic of Cuba and compares it with one from Brazil. A simple description from the Cuban geology and from the involved kaolins deposits is showed. The basic characterization of each kind of kaolin, includes, chemical analyzes, grain size distribution, scanning electronic microscopy, X-ray diffraction and X-ray fluorescence for chemicals. For special assays it had conformed, by a simple axis hand press up to 5 t, test bodies, which had been burnt to the temperatures of 950, 1250 and 1450°C. These results include refractory and contraction results.