Modelling the Relations of Rheological Characteristics with Composition of Plaster Mortar

The rheological properties of fresh plaster mortars, with varied contents of porous fillers and polymer admixtures, have been studied. The quantities of fine limestone and expanded perlite, and dosages of methyl hydroxy ethyl cellulose and ethylene vinyl acetate were varied in the experiment. Effective viscosity (at a shear rate from 0.045 to 5.705 s−1) and the thixotropy of the mixes were determined with rotational viscometer for 18 compositions (according to the design of the experiment). Each of the 18 viscosity curves were described with the Ostwald–de-Waele equation. The Experimental–Statistical models describing the dependencies of the parameters of the rheological model and of mix thixotropy on the composition factors were built on the obtained data. ES-models have allowed the individual and synergetic effects of mix components on the rheological characteristics to be evaluated. The expanded perlite powder can increase the viscosity by two times, probably due to its pozzolanic effect increasing the content of the CSH phase during cement hydration. The thixotropy can be increased by the quantity of limestone. The computational experiments with ES-models have made it possible for the information set, without a noticeable interrelation between rheological characteristics, to be stratified into subsets, in which such interrelations differ significantly.

The Acoustic Performance of Expanded Perlite Composites Reinforced with Rapeseed Waste and Natural Polymers

Lignocelluloses residues from the post-harvest crop are receiving great scientific attention nowadays. Generally, the composite materials based on lignocelluloses waste present low density and weight, and better insulation properties compared with those petroleum-based. This study presents the results of experimental investigations regarding soundproofing capabilities for a composite material based on expanded perlite (EP) and natural polymers matrix (starch) reinforced with rapeseed stalks waste. The preparation of light-weight samples of composites was performed at room temperature through a mechanical mixing process of EP with starch polymers and rapeseed residues until optimum moisture content composition was obtained. Rapeseed stalks long fibers were avoided through the preliminary dry grinding procedure, and the composite was air-dried at room temperature for 48 h. Four samples of composites with different ratio of EP and rapeseed waste were considered. The evaluation of sample sound insulation characteristics was performed using the transfer-matrix method based on a four-microphone acoustic impedance tube. The paper concludes that the proposed composite provides comparative sound insulation capabilities to actual materials, with few particular aspects presented within the paper. Thus, these new materials are promising as a viable alternative to the actual large-scale utilization solutions in soundproofing applications.

Characterization of perlite and expanded perlite from West Sumatera, Indonesia

As a volcanic country, Indonesia is rich in natural mineral resources. One of them is perlite that is spread across several provinces in Indonesia. One of the companies with a mining business permit (IUP) for perlite is CV Abdi Bersaudara, located at Padang Pariaman Regency, West Sumatra Province. Perlite rock can be processed through comminution and heating method. Crushed perlite can be used as sandblasting, slag coagulant, source of silica, foundry and steel industry, special casting sand and metal finishing. Meanwhile, the expanded perlite is a product of heated perlite with a temperature of 700⁰C-900⁰C. This research aimed to investigate the characters of perlite and expanded perlite from West Sumatra. Qualitative and quantitative analysis was conducted by laboratory experiments and testing, such as atomic absorption spectrophotometry (AAS), X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscope (SEM) and optical microscope (OM). Based on the results of this study, West Sumatera perlite can be used as adsorbents, filter media, filler materials and planting media applications.

Expanded perlite commercialization techno-economic analysis in Indonesia

Utilizing a perlite processing plant in Lampung is one of the public services of the Research and Development Center for Mineral and Coal Technology (TEKMIRA). The plant has been fully revitalized and is ready to be developed for commercialization through joint operations. The domestic market for perlite is not as advanced as the world market. These are both opportunities and challenges for the expanded perlite business. Techno-economic analysis can provide an overview of expanded perlite processing and cash flow forecasts during the implementation period of the commercialization project. Based on the financial feasibility indicators, the scenario of the expanded perlite project is feasible to be commercialized. In the proportional scenario, TEKMIRA and business partners will get 70% versus 30%. The alternative scenario of profit-sharing structure is 50% versus 50%. Nevertheless, TEKMIRA still benefits from fixed compensation. These results are expected to attract investors to partner in the commercial business of expanded perlite processing.

Expanded perlite: potential for removing antibiotics from water

This work aims to study the potential of expanded perlite (EP) for amoxicillin (AMX) removal in aqueous solution. For this purpose, chemical, morphological, and textural characteristics of the EP were evaluated, in addition to AMX removal by the adsorption process. The kinetic, isothermal, and thermodynamic parameters were also assessed. The EP presented an isoelectric point of 6.5 and a surface with hydroxyl bands, which favour the adsorption process. Air bubbles were sealed and randomly connected with each other, increasing the surface area relative to the adsorption sites. These non-porous or macro-porous sites demonstrate efficiency in the mechanisms of mass transfer. AMX removal was determined to be a pseudo-second-order process since the adsorption velocity was proportional to the square of the available adsorption sites and indicates heterogeneity in the surface interactions between the adsorbed molecules. Also, the interactions were considered multilayer for low concentrations and monolayer for high concentrations (Sips isotherm). The adsorption process was endothermic and utilised a physical adsorption mechanism. Considering that no modification treatment was applied to the EP, and due to its neutral isoelectric point, macropores, amorphous and dipole induction force (physical adsorption) characteristics, favourable affinity between EP and AMX was observed.