Revista Estratégica vol.10 - Faap

Introduction
The region of the sub-basin of the upper region of the Machado River, sitting in a geology
named intercaleted shales of the Cacoal Formation, is characterized by sedimentary
deposits related to the mineral extraction, with deposits of clay, sand and gravel
that are close to the consumer market. For Souza et al. (2001) the mineral extraction is
one of the human activities with the largest impact, promoting changes in landscape
and ecosystem dynamics.
Despite that, the state of Rondônia has a department responsible for the environmental
licensing for this activity, State Department for Environmental Development
(SEDAM), which grants this license only to enterprises that meet the legal standards,
legislation and submit environmental restoration projects of the areas upon completion
of mining activities. In the region there are approximately about 70 hectares of
already degraded areas, resulting from mineral exploitation, due to the informal sector,
which eventually facilitates the irregularity of this activity.
The existing environmental liabilities, even though being responsibility of the mining
companies, cause conflicts with environmental managers, generating pressures
from society to restore and establish the compatibility between the mineral extraction
activity and the environment. In this sense, the cultivation of fish in intensive and semiintensive
system has proven to be a good strategy for the recovery of degraded areas
from clay mining in the region and has attracted the interest of mining companies,
since the initial investment is low, given the possibility of the construction of tanks at
the moment of the extraction.
Clay mining process in the production of ceramics
According to DNPM apud Radambrasil (1978) there are registered eight producers,
among suppliers and ceramicists, which, according to data provided, extract 1,545m3
per month. This is an average estimate and the extraction of material occurs mainly during
the dry season, between May and October, when the conditions of access and the
actual exploitation work are facilitated.
The mining method employed in the extraction of clay is usually an open-pit, because
the sedimentary deposits are located very near the surface and are covered by
soil layers of small thickness. The method consists of mechanical dismantling of clay
layers or strips by semicircular arches, using equipment such as wheel loader, excavator
or backhoe, and the choice of the proper equipment depends on the shape and depth
of the clay package. The raw material, after extraction, is temporarily stored in a warehouse
near the mine. After the seasoning process, the clay is transported by truck to the
internal tank of the industry.
In general, mining causes a number of unwanted effects that can be named externalities.
Some of these externalities are: environmental change, land use conflicts,
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Estratégica, vol.10(02), dezembro.2010