Syed Fuad Saiyid Hashim

Analysis of Mineralogical Component of Palm Oil Fuel Ash with or without Unburned Carbon

The purpose of this paper is to investigate the mineralogical components of palm oil fuel ash (POFA) with or without unburned carbon by using semi-quantitative X-ray diffraction (XRD). Original POFA taken from palm oil mill was ground in ball mill, producing ground POFA (GPOFA). Unburned carbon was removed by heating the GPOFA at 500 °C for 1 h, producing treated POFA (TPOFA). Neither glassy phase crystallization nor agglomeration of GPOFA particles occurred during the heat treatment. The content of crystalline phase and glassy phase in GPOFA or TPOFA was determined using semi-quantitative XRD analysis internal standard method. The results showed that GPOFA and TPOFA contained 67.22% and 73.89% of glassy phase, respectively, which could be used as pozzolanic materials. The presence of P2O5, K2O and Na2O in POFA was the reason of reducing the melting point of POFA in boiler.

Mechanical Properties of Engineered Cementitious Composite with Palm Oil Fuel Ash as a Supplementary Binder

Palm oil fuel ash (POFA) was used to produce engineered cementitious composite (ECC) in this research where ECC mixtures containing different volume of POFA (up to 55% by weight) of cement, were prepared. Mechanical properties of the resulting ECC mixtures were assessed using the compression, flexural and uniaxial tensile tests. The findings of the study show that the use of POFA improves the mechanical properties of the ECCs. The ECC mix with 1.2 POFA/cement ratio achieved a compressive strength of 30 MPa at 28 days, which is within the normal range of concrete strength for many applications. Moreover, the results portray that the use of POFA should be helpful for achieving strain-hardening behaviour. The increase in the POFA content concomitantly increased the flexural deflection and tensile strain capacities of the POFA-ECC. Furthermore, crack width of the ECC was significantly decreased with an increase of POFA content. In addition, the resulting POFA-ECC is expected to enhance the material greenness and durability.

Shrinkage Characteristics of Green Engineered Cementitious Composites with Varying Palm Oil Fuel Ash Contents and Water-Binder Ratios

The present paper is a part of an extensive study on green palm oil fuel ash engineered cementitious composites conducted at Universiti Sains Malaysia. It specifically investigates the effects of waterbinder ratio (w/b) and palm oil fuel ash (POFA) on the drying shrinkage of engineered cementitious composites (ECCs). W/b values of 0.33, 0.36, and 0.38 were selected. ECC mixes were proportioned to have various ratios of POFA ranging from 0 to 1.2 from the mass of cement. The drying shrinkage measurements were taken at 4, 11, 18, 25, 57, and 90 days. The experimental results show that w/b has a significant effect on the drying shrinkage of the ECC mixtures. Drying shrinkage is remarkably reduced with a decrease in the w/b. The results also showed that drying shrinkage of the composites is considerably reduced when POFA is used in the matrix. The measured drying shrinkage strain at 90 days is only 920×10-6 µε to 1216×10-6 µε for ECC mixtures with high POFA content. The shrinkage strain of the ECC mixtures without POFA at 90 days is nearly 1597×10-6 µε to 1910×10-6 µε.

Case Study of Alluvial Gold Mining at Pulai Mining in Gua Musang, Kelantan, Malaysia

The Pulai fluviatile gold placer deposit stretches along 17 km of the upper reaches of Sungai Galas, Gua Musang, Kelantan. Malaysia Mining Corporation (MMC) had proved-up sizeable reserves following drilling and bulk testing during 1979-1983. The valley alluvium ranges up to 1200 m wide and averages 6.2 m in thickness. The basal gold-bearing Kaksa comprises bimodal channel lag pebble-gravels with the gold especially concentrated immediately above the bedrock and in potholes. The detrital gold is medium to very coarse sand size, moderately sorted, and occurs as fine grains, scaly flakes and platy nuggets. Concentration of gold was especially favoured in two depositional environments. In the slope interruption zones at the confluence of the Galas and Tuang streams, coarse platy gold was deposited while the finer gold was able to be entrapped further downstream above irregular limestone bedrock surfaces. The gold is of relatively high fineness (950-982), and is probably related genetically to acid intrusions. Important primary sources lie near the Kelantan-Pahang border, 35 km SE of Pulai village, while small granite stocks occurring 3 km west of Pulai are an additional likely source [1].

The Influence Wall Thickness of Cement Hollow Spheres towards Compressive Properties of Cement Syntactic Foam

An innovative technique in producing cement syntactic foam (CSF) was proposed in this investigation. This cellular composite material basically consists of a cement matrix embedded with in-house developed cement hollow spheres (CHS). The produced foams incorporated with CHS having different wall thickness, were characterized for compressive strength and then compared with that of plain cement. It was observed that the CSFs were 37%-55% lighter than the plain cement but possessed compromised compressive strength. The comparative compressive properties of CSFs were also evaluated and reported. It was found that the CSF incorporated with thicker-coated CHS showed higher compressive strength compared to that of incorporated with thinner-coated CHS. The failure patterns within the test samples were also examined to determine the failure mechanism. These observations showed that both CSFs exhibited shearing type failure but exhibit different types of crack fractures due to the difference in CHS wall thickness.

Effect of Grinding Aids in Cement Grinding

In fine grinding of cement in a ball mill, it is sometimes impractical to grind finer in a dry state. Even though the chemical reactivity requires the material to be dry ground, it is sometimes necessary to use different breakage machines to obtain the product, but it is usually more expensive, requires more energy and reduces capacity. The economic alternative is to use a grinding aid. Grinding aid or grinding additives refer to substances which when mixed into the mill contents cause an increase in rate of size reduction and flowability. Grinding process of clinker was carried on with a laboratory scale ball mill by varying different type of grinding additives and dosage while the operating conditions of the mill was kept constant. These additives were added into mineral in certain ratio based on the mineral weight and the grinding has been done for a definite time at the same condition. Analysis were then conducted for their size distribution and compaction factor. Results shows that there were significant improvement in size distribution as the dosage and types of grinding additives changes. Different types of grinding additives were found only suitable for clinker grinding while other give no significant results. The results obtained showed that with the addition of grinding additives can improve the grindability by decreasing agglomeration and increase breakage and hence, reducing ball coating Industrials application of grinding additives also give significant improvement in terms of throughput and size distributions.

Cementitious grout for preplaced aggregate concrete: A review

Preplaced-Aggregate Concrete (PAC) consists of two main components, namely the cementitious grout mixture and coarse aggregate particles. Coarse aggregates are placed into the formwork, and then a fresh cementitious grout mixture is injected into the formwork to fill the voids created by the coarse aggregates to form a concrete. PAC has been used in many applications, such as underwater construction, casting concrete sections congested with reinforcement and concrete repair. The cementitious grout properties play an important role for this type of concrete to be successfully constructed. The cementitious grout rheology and physical properties should be practically suitable for the intended usage of the PAC. Therefore, the available literature on the effects of mixture proportions of the grout on the PAC properties is reviewed. The effects of water content on the grout fluidity, bleeding and compressive strength of the PAC are emphasized in this paper.

Effects of using blended binder of RHA and GGBS on the properties of concrete: A review

Concern about protecting and preserving the environment has driven many researchers to innovate the concrete materials in pursuing better mechanical and physical properties of the fresh and hardened concrete. This paper presents an overview of the microstructural properties, workability, and strength performance of concrete incorporated with mineral admixtures from rice husk ash (RHA) and ground granulated blast-furnace slag (GGBS). The substitution of these supplementary cementitious materials as a ternary blended binder concrete has also been included. It was found that, the average of RHA replacement in concrete is about 10%, while for GGBS is in the range of 40 to 50 % replacement of Portland cement. The results from previous studies yield to a better strength and could potentially be used as high performance concrete, but the high replacement with RHA decreased workability and required more water demand due to the micro porous character, high specific surface area and higher in carbon content of the ...

Chemical and Mineralogical Characterization of Malaysian Low Grade Manganese Ore

This paper aims to chemically and mineralogically characterize the Malaysian low grade manganese ore (LGMO). The optical microscope, and scanning electron microscope (SEM) fitted with an energy-dispersive x-ray analyzer (EDX) were used for ore morphology assessment, mineral liberation analysis, particle texture studies, grain size distribution and mineral association assessment. X-ray fluorescence (XRF) and X-ray diffraction (XRD) were used to determine the LGMO’s composition and to identify mineral phases, respectively. SEM images with EDX analysis revealed various optical characteristics of the ore, while XRF results showed that the major elements present in this LGMO are Si, (16.95%), followed by Mn, Fe and Al (at 13.17%, 4.63% and 4.70%, respectively). Phase analysis by XRD meanwhile, revealed the presence of α-quartz, pyrolusite and aluminum-substituted goethite. The natural grain-size distribution and texture (observed using optical and backscattered image analysis) revealed that manganese liberation was observed at particle sizes below 150 µm. This indicates that particle size has a significant effect in the recovery of the manganese oxide. The data and information obtained from this characterization study will aid in the identification and the design of a suitable treatment method for this local LGMO, and with that, the possibility of exploiting this deposit as a local source of manganese.

Modelling and Simulation of Air Classification in Cement Manufacturing

In cement manufacturing, the finish grinding circuit consumes more energy from the raw grinding circuit. Thus, it is necessary for the system to have an efficient air classifier in order to reduce the energy consumption of the cement production. A mathematical model was developed for describing the air classification in the air classifier, in the finish grinding circuit. Samples were collected around the air classifier feed, product and reject. In the laboratory, particle size analysis was done to the samples. Modelling and simulation studies were carried out using JKSimMet software. In order to verify the validity of the model, extensive surveys were performed at different operating conditions. The product and reject of the air classifier for the extensive surveys were predicted by using simulation based on the model that has been developed. The observed and predicted data for particle size distribution agreed closely for the new conditions.