Mass Loss Of Samples Research Articles

High-temperature pyrolysis of petroleum coke and its correlation to in-situ char-CO2 gasification reactivity

The understanding of the pyrolysis behavior of petroleum coke (PC), a by-product of oil refining, is very critical to its energy utilization. Different from most previous work, this investigation particularly focused on PC pyrolysis at high temperatures > 1273 K. The CO2 gasification reactivity of in-situ char, rather than quenched char, was evaluated and correlated to PC pyrolysis behavior at different temperatures. A Chinese PC with sizes below 100 μm was tested on a high-temperature thermogravimetric analyser (TGA). Three sets of tests were carried out for different purposes. The first set was to simultaneously obtain sample mass loss and gas evolution data during pyrolysis through thermogravimetry-mass spectrometry (TG-MS). The second set aimed to collect char samples for subsequent analyses by scanning electron microscopy (SEM) and Raman spectrometry. The third set was to evaluate in-situ char-CO2 gasification reactivity through the TGA. The results showed that, in addition to the commonly-observed primary pyrolysis stage at low temperatures, there was a secondary PC pyrolysis stage at high temperatures > 1300 K. In this process, the gases such as HCN, CO2 and SO2 were significantly released. The observed changes of char morphology suggested a four-staged thermoplastic transformation of the PC during pyrolysis, which has little been discussed previously. At different stages, i.e. softening, plasticizing, resolidification and graphitization, the rate of carbon ordering was different. The in-situ char-CO2 gasification reactivity was found to first increase, then decrease and finally increase again with increasing temperature. Such changes coincided with the thermoplastic state of the pyrolyzed char, but not with the changes of char surface area or carbon ordering. The obtained knowledge is new and highlights the potentially important roles of char thermoplastic state in determining its reactivity towards CO2.

Review on Thermal analysis of Polymer Matrix Composites

Natural fibers are widely used for reinforcement in composite materials and well tried to be effectively exchange fibre strengthened chemical compound composites to some extent in applications like domestic, automotive and lower finish region elements. A few explores have been investigated in last decades to research the conduct of natural fiber composites. The natural fibre strengthened composites are atmosphere friendly, have high strength to weight quantitative relation like artificial optical fiber strengthened composites. Deferential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA) were used to evaluate the thermal properties. TGA is used to measure temperature change and mass loss of samples and DSC enables the measurement of glass transition temperature. This article presents an extensive study on the thermal properties of polymeric composites; the examination on polymeric composites is consistently in the phase of improving the properties.

Surface, Subsurface and Tribological Properties of Ti6Al4V Alloy Shot Peened under Different Parameters.

Ti6Al4V alloy was shot peened by using stainless-steel shots with different sizes (0.09–0.14 mm (S10) and 0.7–1.0 mm (S60)) for two durations (5 and 15 min) using a custom-designed peening system. The shot size was the main parameter modifying the roughness (0.74 µm for S10 vs. 2.27 µm for S60), whereas a higher peening time slightly increased roughness. Hardness improved up to approximately 35% by peening with large shots, while peening time was insignificant in hardness improvement. However, longer peening duration with large shots led to an unwanted formation of micro-cracks and delamination on the peened surfaces. After dry sliding wear tests, the mass loss of peened samples (S60 for 15 min) was 25% higher than that of un-peened samples, while the coefficient of friction decreased by 12%. Plastically deformed regions and micro-scratches were observed on the worn surfaces, which corresponds to mostly adhesive and abrasive wear mechanisms. The present study sheds light on how surface, subsurface and tribological properties of Ti6Al4V vary with shot peening and peening parameters, which paves the way for the understanding of the mechanical, surface, and tribological behavior of shot peened Ti6Al4V used in both aerospace and biomedical applications.

ПРОБЛЕМА ИСПОЛЬЗОВАНИЯ ОТХОДОВ ЛАКОКРАСОЧНЫХ МАТЕРИАЛОВ И ИХ УТИЛИЗАЦИЯ

Актуальность исследования. Коррозия металлов является наиважнейшей проблемой, с которой связаны большие потери металлов. Ежегодно от коррозии безвозвратно теряются сотни тонн металлов, поэтому все исследования, направленные на антикоррозионную защиту металлов, являются целесообразными и актуальными. Цель исследования. Существуют различные методы антикоррозионной защиты металлических деталей, но нет достаточно эффективного метода для конкретных условий антикоррозионной защиты. Целью настоящей работы является использование отходов лакокрасочных материалов для получения антикоррозионных покрытий металлических деталей. Объектом исследования являются отходы лакокрасочных материалов, полученные при окраске автомобилей. Методы: изучение физико-химических свойств отходов; подбор состава для растворения отходов лакокрасочных материалов; разработка рецептуры и получение антикоррозионной мастики; испытание полученного антикоррозионного лакокрасочного покрытия на адгезию, химостойкость, прочность пленки на изгиб, прочность пленки на удар, огнестойкость, морозостойкость; определение наиболее эффективного компонентного и количественного состава полученного покрытия. Выбраны металлические пластинки для нанесения защитного лакокрасочного покрытия, растворы различных соединений для проведения испытаний по определению потери массы опытных металлических образцов Результаты. Разработана и получена мастика на основе госсиполовой смолы и твердых отходов лакокрасочных материалов. Отходы лакокрасочных материалов – потери, получаемые при окраске автомобилей. Госсиполовая смола представляет собой отход масложиркомбината. Полученная мастика прошла испытания в лабораторных условиях по показателям качества в соответствии со стандартами, получены положительные результаты. Проведены эксплуатационные испытания в дорожных условиях, пробег автомобиля составил 12780 км, при исследовании изменения на поверхности покрытия не обнаружены.

Improved pretreatment method for the isolation and decontamination of pyrogenic carbon for radiocarbon dating using hydrogen pyrolysis

Abstract Pyrogenic carbon (charcoal, black carbon, elemental carbon) is one of the most common materials used for radiocarbon dating of terrestrial samples. However, exogenous carbon contamination can compromise the accuracy of radiocarbon ages. This study presents the results of two chemical pretreatments prior to hydrogen pyrolysis (hypy) as improved protocols for the isolation and decontamination of pyrogenic carbon, i) a simple acid-oxidation step (A-Ox/hypy) and ii) acid-base-acid (ABA/hypy). The A-Ox/hypy protocol uses HNO3 and H2O2, while ABA/hypy uses HCl and NaOH. Both pretreatments remove labile and inorganic carbon before hypy, decreasing the potential for in situ production of pyrogenic carbon during the hypy reaction. The effectiveness of each protocol was directly measured on charcoal artificially produced at 350 °C, 450 °C and 550 °C from radiocarbon-free wood, and exposed to environmental contamination for 1–3 yrs. The results show a >94% reduction in carbon contamination for the 450 °C and 550 °C charcoal samples occurred using A-Ox/hypy, but this treatment was less effective for the 350 °C charcoal. A >99% reduction in carbon contamination in all charcoal samples examined occurred using ABA/hypy. The A-Ox/hypy protocol was further tested on cave guano sediments, which had previously reported erroneous dates following simple organic solvent extraction followed by ABA pretreatment. Effective decontamination was achieved using A-Ox/hypy on the guano, which corrected a radiocarbon age reversal. Overall, ABA/hypy effectively decontaminated the charcoals and was a more efficient pretreatment for charcoal than A-Ox/hypy, however resulting in larger sample mass loss. Therefore, ABA/hypy is the recommended protocol for older (>30,000 14C yr BP) charcoal or sediment samples, or where date accuracy is imperative, while A-Ox/hypy represents an improved protocol for the quick and cost-effective measurement of younger samples (

Enhanced Conductivity via Extraction of Hydrocarbon Templates from Nanophase-Separated PEO-LiOTf Polymer Electrolyte Films.

A series of poly(ethylene oxide)–LiOTf electrolyte films were prepared using a variety of hydrocarbon templates as nanofillers, resulting in observable nanophase separation in the polymer electrolyte. Upon partial extraction of the nanofiller template, an enhanced conductivity over 2 orders of magnitude was measured using ac impedance. Scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis were employed to characterize the porosity, composition, and mass loss of template-extracted and nonextracted film samples.

Microstructure and oxidation behavior of plasma sprayed WSi2-mullite-MoSi2 coating on niobium alloy at 1500 °C

WSi2 and mullite co-modified MoSi2 (WMM) coatings were prepared by atmospheric plasma spraying (APS) on the siliconized Nb alloy, and the oxidation behavior was investigated at 1500 °C in air. Single MoSi2 (M) and single mullite modified MoSi2 (MM) coatings were also studied for comparison. The effective protection time (≥500 h) of WMM coating was at least 2.8 and 1.5 times longer than that of M (175 h) and MM (346 h) coatings, respectively. The mass loss of the WMM sample was only 4.41 mg/cm2 after oxidation up to 500 h, which was 77% and 75% lower than that of M (18.88 mg/cm2) and MM (17.59 mg/cm2) samples, respectively. Such an attractive long-term oxidation protection performance of WMM coating was attributed to the incorporation of mullite and WSi2. The presence of mullite and, in particular, of glassy SiO2 contributed to seal cracks. On the other hand, WSi2 gave rise to the growth of a new transition layer of (Nb, Mo, W)5Si3 in the coating, which restrained the outward diffusion of Nb atoms, thus kept the oxide layer intact and stable.

Investigating the influence of instrumental parameters and chemical composition on pyrolysis efficiency of peat

ABSTRACT To track changes in organic matter (OM) in peat soils, analytical techniques are needed that effectively characterize their chemical components. Pyrolysis-gas chromatography/mass spectrometry is a useful method for obtaining a chemical “fingerprint” of OM. To obtain representative fingerprints, the pyrolysis process should be highly reproducible and representative of the original sample; however, these key indicators for successful volatilization are underreported in the literature. We investigated the influence of instrumental parameters (temperatures, heating rates, sample mass), original organic C and nitrogen (N) content, and instrument type (“slow” vs “flash”), on volatilization of different peat samples by monitoring sample mass loss and changes in organic C and N content before and after pyrolysis. Average percent C by mass volatilized (“C pyrolysis efficiency”) across all pyrolysis experiments conducted (mass, instrument types, and settings) was 47.8 ± 1.8%. Sample mass was not a major driver; however, instrument temperatures, heating rate, and original N content had a significant influence on pyrolysis efficiency. N pyrolysis efficiency occurred at significantly higher rates (56.7–75.8%) than C pyrolysis efficiency (45.1–51.6%). N pyrolysis efficiency was also negatively influenced by decreasing concentrations of original sample N, suggesting that N-containing compounds may undergo preferential volatilization in high pyrolysis temperatures. Our data suggest that C pyrolysis efficiency is relatively insensitive to instrumental parameters; whereas when seeking to identify N-containing compounds, appropriate temperatures and heating rates must be chosen. These results provide an expected range for pyrolysis efficiency as a reference for peat samples analyzed with this technique.

High-temperature tribological properties of friction stir processed Al-30Mg2Si composite

ABSTRACT The multi-pass mode friction stir processing (FSP) was applied to Al-30%Mg2Si in-situ composite under optimised conditions. Also, the influence of the pass number increase was evaluated on microstructure and dry sliding wear behaviour of composite at room temperature (RT) and High temperature (HT, 200ᵒC). The optimal RT wear test results were achieved in the three-pass processed (3P) sample.Furthermore, elevating the wear test temperature increased the wear rate and the ACOF of the as-cast composite, compared with RT condition. Nevertheless, covering the worn surface of the FSPed sample by fragmented and evenly distributed Mg2Si particles and improved hardness (specifically in 2P and 3P samples) prevented the severe mass loss in FSPed samples and enhanced the HT wear resistance of Al-30Mg2Si composite. The active wear mechanisms of the as-cast and FSPed composite were also studied at both RT and HT conditions.

Antifungal activity and fire resistance properties of nano-chitosan treated wood

Fungal decay and fire resistance properties of wood treated with nano-chitosan-TPP particles were investigated. Quaternized and non-quaternized nano-chitosan particles crosslinked with a commercial fire-retardant, tripolyphosphate, were prepared from low molecular weight chitosan (with a molecular weight of 50 to 190 kDa). Different treatments were performed on southern yellow pine wood samples via a vacuum impregnation process for both quaternized and non-quaternized nano-chitosan-TPP particles with a concentration ratio of 12% to 4.8% (nano-chitosan to TPP). Both the leached and unleached treated wood samples were exposed to brown rot (Gloeophyllum trabeum) and white rot (Trametes versicolor) fungi according to AWPA standard E10-16. The flammability test was performed with a cone calorimeter according to ASTM standard E1354-15. The heat release rate and the mass loss rate were measured. The results of the fungal tests indicated that the quaternization of the nano-chitosan particles resulted in a reduced mass loss in the pine samples when exposed to Trametes versicolor under leached conditions. Additionally, without the quaternization of the nano-chitosan particles, the mass loss in the pine samples was reduced when exposed to Gloeophyllum trabeum under unleached conditions. The production of nano-chitosan-TPP particles had a significant effect on the fire-retardant activity of the treated wood samples.

The Effect of Eutypella parasitica on the Wood Decay of Three Maple Species

Eutypella parasitica R.W. Davidson & R.C. Lorenz is the causative agent of Eutypella canker of maple, a destructive disease of maples in Europe and North America. The fungus E. parasitica is known to cause wood stain and decay. However, it is not known how effectively it decomposes the wood of the most widespread maple species in Europe. Wood samples of Acer pseudoplatanus L., A. platanoides L., and A. campestre L. were exposed to four isolates of E. parasitica and nine other fungal species for comparison, according to the modified EN 113 standard. After 15 weeks of incubation, mass loss and microscopical analysis of samples showed evidence of colonization and different wood decay potentials among fungal species. A highly significant positive correlation was found between mass loss and moisture content for all fungal species. Similarly, the measured cell wall thickness correlated well with the calculated mass loss of the samples. On average, the fungal species caused the lowest mass loss in A. pseudoplatanus (10.0%) and the highest in A. campestre (12.6%) samples. Among the samples exposed to E. parasitica isolates, the highest mass loss was recorded in A. pseudoplatanus (6.6%). Statistical analysis showed significant differences in mass loss and moisture content between different E. parasitica isolates. Based on the results of staining, we discuss the type of decay caused by E. parasitica. Although E. parasitica isolates caused smaller mass loss of samples compared to other more effective decay species, we should not disregard its capability of degrading maple wood. Because E. parasitica usually infects the lower portion of the trunk, which is the largest and most valuable part of the tree, any damage can cause significant economic and resource loss.

EFFECT OF WELDING PARAMETERS ON WEAR PERFORMANCE OF BORON COATING MADE WITH PTA

It is inevitable that wear on the surfaces occur when especially metal surfaces contact each other. One of the most crucial problems among surface machining is wear problem. In this study, surface of 316 sainless steel was coated with boron via plasm arc method. 160, 165 and 170 current values were utilized as welding parameters. The effect of hard structures occurring over the coating region on substrate wear resistance was investigated when welding parameters used in the study started to solidify after coating. The wear process was carried out on the pin ten disc device using a fixed load (10 N) and sliding speed (0.4 m / s) and at different sliding distances (250 m, 500 m and 1000 m) using stalked grit sandpaper. After the wear process, the characterization of the wear zone was conducted determining it with the help of SEM-EDX. It was determined from optical microscope and SEM analysis that the coating area consisted of cellular, branched and leaf-shaped dendritics; and eutectic structures were formed between these dendritics. As a result of EDX taken from coated region, Fe, B and Cr elements were found. While the highest weight loss occurred in 316 satinless steel with 45 mg, the lowest weight loss was obtained from Boron2 sample with 27 mg. After wear test, low mass loss in samples coated with Boron shows that substrate sample wear resistance increased.

Application of steel slag in cement treated aggregate base course

Steel slag, which can be used as a cementitious material, is widely used in road engineering. However, it is less applied in the base course. The feasibility of the application of steel slag in the road base was examined and the optimal replacement content of aggregate was determined. Different contents of steel slag (30%, 50%, and 70% by volume) were blended into the concrete. The mechanical and durability performance of the mixture were tested. The microstructure and elements distribution were characterized by the scanning electron microscopy (SEM) and the energy dispersive X-ray spectroscopy (EDS). The experiments manifest that steel slag is beneficial for the reinforcement of the strength and shrinkage performance of concrete, making it possible to replace aggregate. The unconfined compressive strength (UCS) change trend at 7d is positively related to cement content. The blend with 50% of steel slag has the maximum strength and stiffness at 4% cement content. In pace with the steel slag amount increases, the freeze resistance and dry shrinkage performance of samples increase, but the temperature shrinkage performance decreases. Besides, the minimum mass losses of samples are those with 50% of steel slag. The microstructure results imply the addition of steel slag increases the amount of hydration products, making the structure tighter and of lower porosity. Molecular simulations also reveal steel slag increases the electrostatic interaction and bonding effect with cement. The addition of steel slag into the road base is feasible, with the best overall performance obtained at the content of 50%. Steel slag mixture has sound economic benefit and potential great environmental benefit compared to limestone mixture. It is worth reminding when steel slag is applied in an engineering project, production process control of steel slag aggregate is required.

Effect of milled fluidised bed cracking catalyst waste on hydration of calcium aluminate cement and formation of binder structure

This study analyses the effect of fluidised bed cracking catalyst (FBCC) waste, milled to nano-sizes and unmilled, on the hydration of calcium aluminate cement after hardening under normal conditions and after thermal treatment of the samples at 1200 °C. Differential thermal analysis (DTA), X-ray analysis (XRD), and electron scanning microscopy analysis (SEM) were conducted. Results of calorimetry studies showed that milled FBCC added up to 5% slightly slows down the hydration processes of aluminate cement, whereas 10% of FBCC accelerates the hydration. The total amount of heat released in the samples with milled FBCC was lower than that in the samples with unmilled FBCC. The thermogravimetry analysis (TG) revealed higher mass loss in samples with unmilled FBCC. Additionally, XRD results after hardening showed that, compared to the samples with unmilled FBCC, the samples with milled FBCC yielded a higher relative intensity of unreacted minerals of cement. After burning the samples at 1200 °C, anorthite crystals were formed in the samples with FBCC. The effect of unmilled FBCC on the hydration process was explained by the ability of the particles to absorb water at the initial hydration stage and subsequently to transfer it to further hydration steps, thereby promoting the formation of crystallohydrates in larger quantities.

The Catalytic Impact of MnO Additive on the Selected Municipal Solid Waste Combustion Behavior Determined by Thermogravimetric Analysis

The thermogravimetric (TG) and kinetic analysis have been performed to evaluate the catalytic impact of MnO additive on selected municipal solid waste (SMSW) combustion behavior. Nineteen kinds of the SMSW have been collected, cleaned, dried, and grounded to the size of less than 1 mm and then mixed with the same mass ratio. The addition of an additive to the SMSW was completed by virtue of blending the10 mg SMSW with 0.5 mg the MnO powder and then was ground thoroughly in the mortar to obtain the homogeneous mixture of SMSW/5%MnO. Subsequently, the sample was brought into the crucible uniformly. The sample combustion in the chamber was carried out under non-isothermal conditions at the controlled heating program of 10 and 30 oC/min, a temperature range of 25-1000 oC, and an air atmosphere flowrate of 100 ml/min. The sample mass loss during temperature and time escalation was recorded by a computer automatically to be a TG curve. The 1st derivative of the TG curve to the temperature or time represented the rate of sample mass loss and denoted as the derivative thermogravimetric (DTG) curve. In accordance with both TG and DTG curves, then the characteristic temperature parameters were determined. The Coats-Redfern method has been adopted to evaluate kinetic parameters in this study. To understand the catalytic effect of the MnO, the blending SMSW/5%MnO results were compared with the pure SMSW ones. The results indicated that the MnO additive has promoted the initial temperature decomposition toward the lower value and provoked the increasing mass loss rate. Moreover, the presence of MnO also decreased the activation energy in the main combustion region. The overall results revealed that the MnO additive has significantly impacted the dynamic of thermal decomposition during the combustion processes.

Volatility Study of Amino Acids by Knudsen Effusion with QCM Mass Loss Detection.

This work presents a new Knudsen effusion apparatus employing continuous monitoring of sample deposition using a quartz-crystal microbalance sensor with internal calibration by gravimetric determination of the sample mass loss. The apparatus was tested with anthracene and 1,3,5-triphenylbenzene and subsequently used for the study of sublimation behavior of several proteinogenic amino acids. Their low volatility and thermal instability strongly limit possibilities of studying their sublimation behavior and available literature data. The results presented in this work are unique in their temperature range and low uncertainty required for benchmarking theoretical studies of sublimation behavior of molecular crystals. The possibility of dimerization in the gas phase that would invalidate the effusion experiments is addressed and disproved by theoretical calculations. The enthalpy of sublimation of each amino acid is analyzed based on the contributions in two hypothetical sublimation paths involving the proton transfer in the solid and in the gas phase.

Testing of lubricating properties of mixtures of diesel and RME biofuels with the addition of linoleic acid

In connection with the limited resources of fossil fuels and the reduction of emissions and stimulation of agricultural areas, a very important indication is the search for alternative fuels – biofuels. The article presents the results of testing the lubricating properties of selected fuel mixtures. The lubricity of diesel fuel (DF), DF with 7% content of methyl esters of rapeseed oil fatty acids (RME), technical linoleic acid and DF with 7% content of RME and 10% content of technical linoleic acid was tested. The research was carried out on the author's research stand in the amount of 20 dm3 of mixture. Four parameters were taken into account: mass loss of samples, the footprint area of cooperation, diameter of equivalent wheel and average value of the coefficient of friction. It has been shown that the addition of linoleic acid to diesel fuel containing RME causes a significant increase in the mass loss of the samples and the footprint area of cooperation as well as its diameter of equivalent wheel, during lubrication with such a mixture. As a result of the addition of linoleic acid, no positive results were obtained, as the lubricating properties in this case deteriorated. Therefore, it is justified to continue looking for fuel additives that will eliminate this negative effect.

Compressive and Corrosion Properties of Lotus-Type Porous Mg-Mn Alloys Fabricated by Unidirectional Solidification

Lotus-type porous Mg-Mn alloys were fabricated by solid-gas eutectic unidirectional solidification (the Gasar process) by controlling and optimizing the process parameters. The microstructures, compressive properties and corrosion properties in a simulated body fluid solution were investigated. Porous pure Mg was prepared with a preferentially oriented (11$$ \bar{2} $$2) plane, whereas the Mg-2 wt pct Mn alloy showed a preferentially oriented (10$$ \bar{1} $$3) plane. Mn addition refined the grains, improved the Mn precipitates, activated the {10$$ \bar{1} $$2} twin at the end of the pores and increased the compressive strength from 64 MPa for pure Mg to 74 MPa for 1 wt pctMn and 80 MPa for 2 wt pct Mn. Electrochemical tests showed that 2 wt pct Mn addition could decrease the corrosion current from 1.84 × 10−3 to 4.22 × 10−4 A cm−2. Immersion tests suggest that 2 wt pct Mn addition reduced the sample mass loss, which indicated a better corrosion performance, and exhibited a smaller decrease in compressive strength compared with that of the porous pure Mg. This work shows that the Gasar technique can be a promising fabrication method to prepare lotus-type porous Mg-Mn alloys which are more attractive for application in degradable biomaterials engineering.

Anatomical, Chemical and Mechanical Characteristics of Beech Wood Degraded by Two Pleurotus Species

The aim of this study was to determine the destructive capabilities of the two white rot fungi Pleurotus cornucopiae (Pc) and P. eryngii (Pe) compared with the standard fungus Trametes versicolor (Tv) on beech wood samples after 60 days of incubation. Understanding of the white rot decay is important as it is necessary for the development of effective solutions for wood protection. Measurements of mass loss, chemical, mechanical properties and light microscopical investigations were conducted prior to and after incubation. Mass loss of samples was found to be 9-22 % depending on fungi species. Impact bending strength is not as sensitive as presumed in classical literature. Light microscopy analysis revealed that decay patterns were similar for both fungi. Wood cell wall thinning, fungal colonization hyphae were also the same for both fungi. Results indicated considerable wood attack by both Pleurotus species, Pc being more destructive than Pe.

Combined effects of salts and wetting–drying cycles on granite weathering

Granite is one of the most applied building materials globally. Salt weathering affects the aesthetic properties of granite and reduces its durability. Accelerated granite weathering tests were conducted to study the combined effects of salts and wetting–drying cycles. Granite samples were soaked in solutions of Na2SO4 and MgSO4 at different concentrations (0%, 5%, 10% and 20%) before drying. The mass loss, colour, roughness and surface hardness of the granite samples were measured after repeated cycling (0, 10, 20, 30, 40, 55, 65, 80, 90 and 100). The key research findings were as follows: (1) an increase in the number of wetting–drying cycles affected the properties of the granite samples significantly (i.e. mass loss, colour, surface roughness and hardness). (2) The effects of Na2SO4 on the accelerated weathering of granite were greater than those of MgSO4. (3) Higher salt concentrations (0%–20%) accelerated granite weathering.