Dr.-Ing. Stefan Vogt

Methods of evaluation for raw material suitability and body optimization (Part 1)

Figures/Bilder: Stefan Vogt

»1 Ternary diagram showing natural ranges for roof tiles, floor filler blocks, checker bricks and solid bricks acc. to Winkler. 1954 [38] (19 roof tiles,19 floor filler blocks, 6 checker bricks, 3 solid bricks)

Figures/Bilder: Stefan Vogt

»2 Ternary diagram with natural ranges for roof tiles, vertically perforated bricks and solid bricks acc. to Schmidt. 1973 [39] (80 roof-tile bodies, 35 vertically perforated brick bodies and 35 solid brick bodies)

»3 Ternary diagram with natural ranges for roof tiles, floor filler blocks, soft-mud bricks, vertically perforated bricks and engineering bricks acc. to author’s own readings in recent years (28 roof tile bodies, 4 floor filler block bodies, 2 soft-mud brick bodies, 63 vertically perforated brick bodies and 21 engineering brick bodies)

»4 Placement of clay and non-clay minerals in the Winkler ternary diagram according to statistical investigation of granulometric expectation values by the author [33, 36]

»5 Revised Winkler diagram for roof tiles, floor filler blocks, soft-mud bricks, vertically perforated bricks, solid bricks and engineering bricks (broken line – core region <80%, solid line – total natural range)

»6 Natural range of especially frostproof roof tiles acc. to Ruppik [70] (various freeze-thaw-cycle /FTC repetition levels) and area of highest packing density with <25% pore volume after tempering of specimens at 600° C (Author’s own research)

$»7 Hypothetical through-fraction curves for the highest flexural/compressive strength after drying, based on data from [81, 82]$

»7 Hypothetical through-fraction curves for the highest flexural/compressive strength after drying, based on data from [81, 82]

»8 Augustinik diagram from 1975 [50, 51] for diverse heavy clay products

»9 Revised Augustinik diagram for various heavy clay products

»10 Quartz inversion points ranging between 600° C and 550° C taken from dilatometric curves, as functions of free quartz content (own testing of 124 clays and body compositions)

»11 Complex mineral analysis by evolutionary methods using the SimClay program

A number of veteran methods for evaluating the suitability of raw materials, including the Winkler diagram, the Augustinik diagram and material qualification testing according to Freyburg, are critically examined and accommodated to presently employed product qualities and production technologies. Based on past experience with quantitative mineral analysis, mineral compositions considered optimal for diverse heavy clay product categories are stated. In Part 2, a procedure is described for the pre-optimization of body compositions by means of simple search techniques, linear optimization methods and algorithms.

1 Introduction

For the evaluation of raw material suitability and the optimization of body compositions for heavy clay production, all matters concerning the following two topics must be clarified:

Which properties must the product display?

Which production technology is to be applied to the product?

The properties required of heavy clay products are customarily described in country-specific standards. Beyond such standards, however, additional criteria may also apply to a product’s particular aesthetic appeal in terms of shape, colour or chromatic interplay.

A broad range of production...

Robert Thomas Metall- und Elektrowerke GmbH & Co. KG

Methods of evaluation for raw material suitability and body optimization (Part 1)

1 Introduction

Related articles:

Increasing brick body strength by adjusting the particle-size distribution

Energy-saving methods of conditioning green brick bodies for low-temperature drying

Differences in the production-related properties of the three primary clay minerals kaolinite-illite-montmorillonite (Part 2)

Reduction of the thermal conductivity of brick bodies through fast firing

Influence of mineral additives on the drying and sintering behaviour of brick bodies, Part 2

1 Introduction

ZI 05/2015

ZI 05/2015

Related articles:

Increasing brick body strength by adjusting the particle-size distribution

Energy-saving methods of conditioning ­green brick bodies for low-temperature drying

Differences in the production-related properties of the three primary clay minerals kaolinite-illite-montmorillonite (Part 2)

Reduction of the thermal conductivity of brick bodies through fast firing

Influence of mineral additives on the drying and sintering behaviour of brick bodies, Part 2

Energy-saving methods of conditioning green brick bodies for low-temperature drying