Untitled in english

Author(s)

Nelson Camurugi Senhorinho Silva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola Politécnica (EP/BC)
• Defense date: 2001-06-05

Examining board members

Giorgio Francesco Cesare de Tomi; Adriano Caranassios; Lineu Azuaga Ayres da Silva

• Advisor: Giorgio Francesco Cesare de Tomi

Abstract

Limestone extraction for cement manufacturing is one of the most important non-metallic industries in Brazil. Cement is one of the most important construction raw materials for engineering applications, with large market opportunities & projected growth. The main raw materials for cement are limestone and clay, that are usually mined in mines located near to the cement plants, always aiming to minimize haulage costs. The wide diversity of cement products (mortar, initial high strength cement, mineralized clinker, etc.) and the increasing competitivity in cement production, together with the need for both quality and environmental control, usually means that recoverable reserves of existing limestone deposits must be maximized. The increasing need of product quality in the cement industry has lead to more specific requirements of raw material homogeneity and low cost supply of ore (limestone, clays). The problem is to define how much and what is the proportion of raw material blend and how should be scheduled the extraction at the mine, not only to meet blending under chemical and mineralogical restrictions, but also to ensure profitable extraction based on currently available mining and crushing technologies. This research project aims to develop a methodology for obtaining the ultimate pit and long term mining schedule of limestone for cement. The methodology is based on the most moderns and established techniques for mine optimization and sequencing. Themethodology proposed was then applied and improved at the mine sites of large cement producers in Brazil. The resulting methodology allow maximum recovery from the limestone deposit, ensuring the maximum possible economical profit, with proper environmental planning and quality control of the raw materials for cement processing, through the detailed definition of the pit limits for the ultimate pit and all the mining phases. These results are directly related to the mining schedule of the deposit until the end of the life of the mine. Therefore, it avoids the mine to shut-down early, which is somewhat common in various limestone quarries for cement manufacturing. (AU)