Comparative Analysis of the Strength Distribution for Irregular Particles of Carbonates, Shale, and Sandstone Ore

• Main Authors: Alona Nad, Daniel Saramak
• Format: Article
• Language: English
• Published: MDPI AG 2018-01-01
• Series: Minerals
• Subjects: strength distribution; dolomite; shale; sandstone; Weibull modulus
• Online Access: http://www.mdpi.com/2075-163X/8/2/37

The article presents the results of investigations on three lithological types of Polish copper ore: sandstone ore, carbonate ore, and shale ore. According to X-ray diffraction analysis, sandstone samples can be classified as sandstone with dolomite binder and partly clay binder; shale—as dolomitic slate with a high proportion of clay with elevated organic matter content; while dolomite has a high organic content. Five particle-sized fractions (16–18 mm, 18–20 mm, 20–25 mm, 25–31.5 mm, and 31.5–45 mm) of each lithological type were prepared. A single-axis slow-compression test was performed on single particles to determine the value of the crushing force. The Weibull distribution was used to approximate the strength distribution models and cumulative strength distribution functions for each of the materials. The residual deviation and non-linear correlation coefficient were calculated in order to assess the fitting of the model function to empirical data. In addition, the impact of particle size on the strength of the raw material was separately investigated for the hard (dolomite and shale) and soft brittle material (sandstone).