Report 3: AQIRF085-2023RD6 Milestone 1.2

Report 3: AQIRF085-2023RD6
Milestone 1.2

This report presents the findings of an initial investigation into the use of coal combustion products
(CCPs) from the Millmerran Power Station—specifically, Bottom Ash and Run-of-Station ash—for the
stabilisation of black clay soils. These soil types, known for their high plasticity and poor engineering
performance when wet, pose significant challenges for infrastructure development.
A series of strength (UCS) testing has been previously conducted using CCPs from Millmerran Station to
stabilise highly organic black cotton clay. These tests have had limited success and have not achieved
the desired strength of 1.5MPa. A core focus of this report is to examine the reactivity and material
characteristics of Millmerran CCPs using a combination of microscopy techniques (SEM) and elemental
analysis (EDS). These methods are used to assess particle morphology, chemical composition, and
other key properties that influence pozzolanic activity, binding potential, and overall performance when
used in stabilisation or blended cement systems.
In addition to this primary investigation, the report also aims to provide an overview of CCP production
across coal-fired power stations in Queensland. This secondary objective involves identifying and
mapping key locations where CCPs are generated, with the goal of evaluating potential supply chains
and sourcing opportunities for future large-scale use in infrastructure and soil improvement projects