Skip to main navigation Skip to search Skip to main content

The needle penetration test for predicting coal strength

  • CINER Group
  • Hacettepe University

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

The coal strength parameter is used in operations such as the selection and design of mechanical excavators and coal crushing/grinding equipment. However, coring or cutting prismatic specimens from coal for the standard strength tests is difficult, and sometimes not possible. For this reason a method for the indirect determination of coal strength from easy tests would be useful. In this study, the predictability of coal strength from the needle penetration test was investigated. This is a very easy and practical test method. Point load and needle penetration index (NPI) tests were carried out on coal specimens from Çayirhan coalfield in Turkey. The point load indexes were converted to the uniaxial compressive strength (UCS) values by using the general conversion factor. The UCS and NPI values were evaluated using regression analysis. A strong linear relationship was found between the two parameters. The conversion factor for the UCS-NPI ratio is 0.35 for the tested coal samples. It is concluded that the UCS of coal can be predicted from the NPI.

Original languageEnglish
Pages (from-to)587-591
Number of pages5
JournalJournal of the Southern African Institute of Mining and Metallurgy
Volume117
Issue number6
DOIs
Publication statusPublished - Jun 2017

Keywords

  • Coal
  • Needle penetration index
  • Uniaxial compressive strength

Fingerprint

Dive into the research topics of 'The needle penetration test for predicting coal strength'. Together they form a unique fingerprint.

Cite this