II Metal Extraction

Applied Statistical Analysis on the Calcination Process in the Ferronickel Production

Fabio M. Soares, Denis Shevchenko, Alexey Levchenko, Alexey Avdeev, Alexander Vodin, Vitaly Rudik and Stanislav Kovalchuk

Abstract Ferronickel is mainly produced by the RKEF (Rotary Kiln Electric Furnace) process. The ore is extracted, crushed and dried before calcination. Rotary kilns are usually about 100 m long and rotate to facilitate material flow. Due to this length, in addition to rotation speed, the material takes a variable time to cross the whole kiln, and thereby changing the chemical and temperature profile, making the control of calcine temperature a great challenge. However, statistical analysis are a great tool for finding interesting patterns that are of valuable help to control the kiln variables, that are very sensitive to inertia caused by rotation and changes in temperature profile. We present a study based on real data taken from a processing plant, whereby we applied data mining techniques to extract information on which variables have influence on kiln’s key performance index variables, such as calcine temperature.

Keywords Rotary kiln control Applied statistics Chemical process

Introduction

Statistics has been applied on process control for decades by means of techniques like Analysis of Variance (ANOVA), Statistical Process Control (SPC), Principal Components Analysis (PCA) and Projection to Latent Structures (PLS) [1]. These techniques offer great help to control very sensitive process variables.

Nowadays every industry maintains huge process databases that implicit reflect the process dynamics, whereby these data provide the underlying base for all kinds of process analysis. In this sense, it seems reasonable to look back at those data to examine some unexpected deviation, or investigate some process phenomena [2]. In addition, the history database hides invisible patterns, even for experts in operation,

F.M. Soares (H) • D. Shevchenko • A. Levchenko • A. Avdeev • A. Vodin • V. Rudik • S. Kovalchuk

Federal University of Para, Belem, Brazil e-mail: This email address is being protected from spam bots, you need Javascript enabled to view it

© The Minerals, Metals & Materials Society 2017

A. Allanore et al. (eds.), Materials Processing Fundamentals 2017,

The Minerals, Metals & Materials Series, DOI 10.1007/978-3-319-51580-9_2

but detectable by statistics [3]. Understanding these patterns is fundamental for carrying out a great control.

In this work, we present a statistical procedure to find patterns in the calcination phase of the Ferronickel RKEF (Rotary Kiln Electric Furnace) process.

 
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