A one-dimensional mathematical model was developed for the simulation of limestone calcination in rotary kilns. The model is comprised of ordinary differential equations derived from mass and energy conservation principles. The system of equations is solved by a fourth-order Runge-Kutta method. The model predicts, in the axial direction, temperature profiles for the bed of particles, the gas ph...

This study aims to determine the major elements of Portland cement type I and II (CEMI and CEMII) in a cement factory in north Tunisia and which metal elements are introduced into the production process. We determine also the metal input rate and their distribution at the entrance and exit of the process. The major elements were analyzed and the trace elements (Arsenic, barium, lead, mercur...

Abstract This paper investigates different approaches to develop soft sensors from multi-rate sampled data. The data lifting approach consists of two steps, identifying a model with a slow/lifted sampling period and extracting a fast model. Approaches based on direct extraction and linear regression are briefly reviewed, followed by reformulating the task as an unconstrained optimization proble...

Hazardous wastes from various industrial processes are normally incinerated with rotary kilns in order to comply with current environmental regulations. They have often very complicated chemical compositions in a variety of physical forms and difficult to characterise. The complex transport phenomena within the incinerator are not well understood, and the incineration process expects large unce...

Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. Th...

We consider methods for modeling the temperature fields inside a rotary tubular kiln and in the lining of the oven. These models are used for creating a control system that supports the necessary technological parameters and reduces the heat loss through the kiln body to the environment. Two-dimensional modeling of the processes inside the kiln confirms the applicability of a unidimensional mod...

AIM To report the hydration mechanism of white mineral trioxide aggregate (White MTA, Dentsply, Tulsa Dental Products, Tulsa, OK, USA). METHODOLOGY The chemical constitution of white MTA was studied by viewing the powder in polished sections under the scanning electron microscope (SEM). The hydration of both white MTA and white Portland cement (PC) was studied by characterizing cement hydrate...

We are pleased to submit our white paper report on the Reduced Emission Oxygen (REO) kiln. The document outlines the basic technology and the operational differences between the REO kiln and a conventional cement plant. We trust that you will find the results as exciting as we do and look forward moving this next generation cement technology to market. The REO kiln represents a paradigm shift i...