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Assessment of Foundry Chromite Sand Crushability under Thermal-Mechanical Loading

Kabasele Jonathan K., Nyembwe Kasongo D., Polzin H.

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 3

16--21

EN

When used for sand casting, foundry sand is stressed in several ways. These stresses, thermal and mechanical, compromise the grain integrity, resulting in size reduction and the production of small particles to the point where the sand is no longer viable for sand casting. This study evaluates the crushability of chromite sand, a crucial characteristic for determining how resistant sand is to size reduction by crushing. To replicate the heat and mechanical strain that sand is subjected to during the industrial sand-casting process, a sinter furnace and rod mill were employed. After nine minutes of heat and mechanical stress application, the crushing ratio, which was used to gauge the crushability of chromite sand, ranged from 1.72 to 1.92 for all samples. There were differences in the rate at which fine particles were produced among the samples, with sample E producing the highest proportion of fine particles in the same length of time. Understanding the properties that control the crushability performance of chromite sand will enable foundries to buy chromite sand with higher recycling yield, reducing the environmental impact of waste foundry sand and eliminating the risk to the workforce's pulmonary health in line with the current industry standards. Foundries will also be able to optimize the current industrial process while continually pushing for innovative foundry technologies and materials.

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Effects of South African Silica Sand Properties on the Strength Development and Collapsibility of Single Component Sodium Silicate Binders

Banganayi F. C., Nyembwe K., Polzin H.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 3

5--12

EN

This study shows the results of the investigation of the strength performance, and residual strength of a single component inorganic binder system Cast Clean S27®. The study was conducted using three different foundry sand sources in South Africa. Sample A is an alluvial coastal sample, sample B is an alluvial riverbed sample and Sample C is a blasted sample from a consolidated quartzite rock. The binder was also cured using three different curing mechanisms. The aim of the investigation was to determine the variation of strength performance and residual strength between the different South African sand sources based upon the physical and chemical properties of the sand sources. The moulding sand was prepared using three possible curing mechanisms which are carbon dioxide curing, ester curing and heat curing. The strength measurements were determined by bending strength. Sample A and sample C sand had good strength development. Sample B sand had inferior strength development and excellent high temperature residual strength. The study showed that the single component inorganic binders have good strength development and low residual strength. The silica sand properties have major contributing factors on both strength development and residual strength. The degree of influence of silica sand properties on strength performance and residual strength is dependent on the time of curing and method of curing.

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Anwendung und eigenschaften innovativer anorganischer binder für die kernherstellung

Tilch W., Polzin H.

Archiwum Odlewnictwa

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2004

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R. 4, nr 13

219--224