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1. (WO2018195624) MANUFACTURING PROCESS OF POZZOLAN WITH COLOR CHANGE AND POZZOLAN THUS OBTAINED

Pub. No.:    WO/2018/195624    International Application No.:    PCT/BR2018/050120
Publication Date: Fri Nov 02 00:59:59 CET 2018 International Filing Date: Tue Apr 24 01:59:59 CEST 2018
IPC: C04B 7/47
C04B 14/16
C10L 5/02
Applicants: DYNAMIS ENGENHARIA E COMÉRCIO LTDA.
Inventors: FERREIRA, Guilherme Martins
FABIANI, Luis Filipe Von Rainer
DE PINHO, Luiz Felipe
BORGES, Rodrigo De Sousa
Title: MANUFACTURING PROCESS OF POZZOLAN WITH COLOR CHANGE AND POZZOLAN THUS OBTAINED
Abstract:
The present invention refers to a manufacturing process of artificial pozzolan which has the final color gray. In order to perform the processes in the desired way, the kiln atmosphere shall contain low oxygen concentration and the presence of reducing agents. However the presence of carbon monoxide at the kiln outlet is not desirable, due to environmental impacts and the increase in specific heat consumption of the kiln. So the process described in this invention comprises the following steps: heating (1), which consists of heating the raw materials to a temperature between 100-350°C until drying of the material to a moisture mass fraction of 0-5% (wet basis); mixing (2), which consists of mixing the dry raw materials from the heating process with the right proportion of fuel, from 1% to 5% in mass fraction, according to the concentration of hematite present in the raw material; calcining (3), which consists of heating the fuel and raw materials blend to a temperature between 700-900°C, with oxygen concentration between 1-5% and, finally, cooling (4), which consists of an initial step of rapid decrease in pozzolan temperature until 600°C and a final step of slow decrease in pozzolan temperature until 120°C.