Sulfuric Acid Research Articles

Efficient biodiesel production by sulfonated carbon catalyst derived from waste glycerine pitch via single-step carbonisation and sulfonation

Glycerine pitch is a highly alkaline residue from the oleochemical industry that contains glycerol and contaminants, such as water, soap, salt and ash. In this study, acidic heterogeneous glycerol-based carbon catalysts were synthesised for biodiesel production via single-step partial carbonisation and sulfonation using pure glycerol and glycerine pitch, producing products labelled as SGC and SGPC, respectively. Carbon materials were obtained by heating glycerol and concentrated sulfuric acid (1:3) at 200℃ for 1 h. The produced SGC and SGPC displayed high densities of sulfonic group (–SO3H), i.e. 1.49 and 1.00 mmol·g−1, respectively, alongside carboxylic (–COOH) and phenolic (–OH) acid. In the catalytic evaluation, excellent oleic acid conversions of 96.0 ± 0.4 % and 92.4 ± 0.5 % were achieved using SGC and SGPC, respectively, under optimised reaction conditions: 1:10 M ratio of oleic acid to methanol, 5 % (w/w) catalyst, 64℃ and 5 h. SGPC was found to be recyclable with 68.5 % conversion after the 6th cycle, which was attributed to the loss of –SO3H and catalyst deactivation by the deposition of oleic acid on its surface. Remarkably, despite the impurities present in the glycerine pitch, the obtained results demonstrated that the reactivity of SGPC is comparable to SGC and superior to that of commercial solid acid catalysts, which demonstrated that the presence of impurities appears to have minimal impact on the production of carbon materials and their properties.

Prospective life cycle assessment: Identifying the most promising methods for sustainable cellulose nanocrystal production

Concerted endeavors are presently in progress to discern eco-friendlier methods for cellulose nanocrystals (CNC) production, negating the conventional reliance on hazardous concentrated sulfuric acids. Despite the proliferation of methods purported to be environmentally sound, their assertions often lack rigorous scrutiny, relying on theoretical postulations. This study presents the first prospective glimpse into their environmental performance utilizing a life cycle assessment (LCA) methodology from cradle-to-gate. The results transpired that many of the vaunted environmentally-friendly methods resulted in higher environmental loads compared to the traditional method, due to lower conversion rates and higher reaction energy demand. Notably, only specific methods demonstrate lower endpoint impact scores, including deep eutectic solvent extraction (−48 %), ammonium persulfate-assisted oxidation (−62 %), sulfuric acid hydrolysis in glycerol medium (−56 %), and enzymatic hydrolysis (−40 %). Their primary green attributes associate with the utilization of solvents carrying lower climate impact and toxicity level. The reaction stage carries the heaviest burden due to the increased energy required to counteract modest reactivities of the milder solvents. As mitigation strategies, heat integration and by-product recovery for energy generation were explored, resulting in emission reductions of 11–26 % and 41–68 %, respectively, across the proven eco-friendlier methods. This study comprehensively validated a roster of genuinely green candidates, offering a more sustainable prospect than traditional methods and paving the way for large-scale green CNC production.

Effectiveness of Jute Cellulose Nanocrystal Reinforcement into Biodegradable Packaging “Sonali Bags®”

In an age marked by environmental consciousness, “Sonali Bags®” have emerged as promising substitutes for single-use plastic bags, invented in Bangladesh. It is a jute cellulose-based, totally biodegradable, compostable, recyclable, and environment-friendly biopolymer. However, certain physical limitations have hindered its widespread consumer appeal. To address these challenges, this study pioneers the integration of Jute Cellulose Nano-crystals (JCNC) into Sonali bags, with the objective of enhancing their physical properties. JCNC, obtained through a meticulous 64% concentrate sulfuric acid hydrolysis process, has been reinforced with Sonali Bags at varying loadings (0, 0.1, 0.2, 0.3, and 0.4 wt%). The SEM analysis showed spherical cellulose nanocrystals with high crystallinity and distinctive tear-like features on the nanoparticle's surface. Furthermore, the SEM micrographs depicted that JCNC loading up to 0.2% helped reduce the pore formation of bio-composite. Moreover, the thermal properties increased significantly, and tensile strength increased by approximately 37% MPa after reinforcing JCNC with Sonali Bag. The water-resistant capacity of 0.2% CNC reinforced film was about 30% better than other compositions. The JCNC-reinforced composite materials were found to moderate the degradation rate, contributing to the prolonged sustainability of these biodegradable solutions.

Hydrology controls sulfuric acid-mediated weathering in an orogenic regime of southwestern Taiwan

Chemical weathering is a pivotal geochemical process that shapes the carbon cycling and climates in the critical zone. Among its critical drivers, river discharge holds a particular significance, especially in the orogenic landscapes. Here, we examined the impact of discharge on mineral weathering in southwestern (SW) Taiwan by analyzing river water chemistry across a wide discharge range. Current observations indicated that carbonate contributes significantly to total weathering (50–80 %), with sulfuric acid accounting for one-half to two-thirds of carbonate weathering. A statistically strong correlation between river discharge and sulfuric acid-mediated carbonate weathering was highlighted, while the silicate weathering remained constant. This relationship suggests an increased influx of fresh minerals, such as pyrite, into the weathering regime as water flow increases. Our model identifies a critical discharge threshold of 4.6 m3 s−1, determining whether mineral weathering acts as a net source or sink of CO2. Consequently, mineral weathering in SW Taiwan acts as a net CO2 sink during dry periods but turns into a net source during wet periods. Through analyzing a decade of daily discharge data, we found mineral weathering in SW Taiwan is a net CO2 source, with a 2.6-fold increase in annual mean discharge causing a 3.8-fold increase in net CO2 flux. This pattern is likely to be applicable to other similar minerals containing mountain-building regions, highlighting the significant role of hydrology in determining weathering sources and their potential impact on the carbon cycle balance.

Vitriol attack on a young woman in Greece: The story of Ioanna's response.

An acid attack is a deliberate act of violence. Sulphuric acid is thrown at a person's face and body with the intention of harming and disfiguring the victim. Sulphuric acid is a dangerous weapon which can cause very serious injuries including severe skin damage, blindness, significant disfigurement and/or permanent disability. We report the case of Ioanna, a 34-year-old woman who was attacked with vitriol by a jealous woman in May 2020. Following her admission to hospital, where Ioanna was an inpatient for 85 days, she underwent nine operations. Since her discharge she has undergone ten more, with further interventions likely in the future. In addition, she has undergone various treatments and procedures to restore her skin. Ioanna's courage and strength has inspired thousands of young children and adults who cope with a variety of health problems.

Extraction of arsenic from fine dust of copper smelters by reduction roasting with natural gas

One of the current trends in the complex processing of fine dust from copper smelters is their direct leaching with sulfuric acid. As practical results show, high reliable technological parameters are not achieved due to the high content of arsenic in dust. During sulfuric acid leaching of dust, arsenic is distributed between the lead cake and the solution at a ratio of 40 and 60%, respectively. The redistribution of arsenic between leaching products significantly reduces the technological performance and leads to the accumulation of arsenic in the technological scheme. The paper presents the results of comprehensive studies of the elemental and phase composition of fine dust from one of the copper smelters in Kazakhstan. In the initial dust, along with the main phases presented in the form of lead and zinc sulfate, the following typical components were found: oxides of copper, lead, zinc and copper and zinc ferrites. Arsenic is found in two forms—As(III) and As(V). The laboratory installation and technique for conducting reduction roasting of dust with natural gas are presented. The influence of roasting duration, temperature and natural gas consumption on the extraction of arsenic from dust was studied. It has been established that almost complete, up to 99%, extraction of arsenic from dust is achieved with optimal technological roasting parameters: duration τ = 40 min.; natural gas consumption is 1.5 times higher than the stoichiometrically required amount for the reduction of As2O5, and temperature 500 °C.

Electrokinetic-enhanced sulfuric acid leaching of uranium from sandstone uranium ores

Solute transport in conventional acid leaching of sandstone uranium ores is limited by diffusion and convection, resulting in extended leaching cycles. This study described an electrokinetic-enhanced method for leaching sandstone uranium ore with sulfuric acid and was intended to investigate the impacts of potential gradients on leaching efficiency. Electrokinetic horizontal column leaching experiments were conducted on sandstone uranium ore. After 20 h of leaching, the uranium leaching efficiencies were 54.90 %, 56.36 %, 68.33 %, and 82.04 % for potential gradients of 0, 0.5, 1.0, and 2.0 V/cm, respectively. The uranium leaching efficiency of sandstone at a 2.0 V/cm potential gradient was 27.14 % greater than that at a 0 V/cm potential gradient, and the leaching time was decreased by approximately 40 % at the same uranium leaching efficiency. Analyses of the chemical fraction of uranium, XRD and SEM-EDS showed that the applied potential gradient facilitated solute transport during leaching, thus accelerating the leaching efficiency of adsorbed uranium, tetravalent uranium, and uranium encapsulated in lattices of silicates and primary and secondary minerals in sandstone uranium ores. Therefore, electrokinetic action is excellent for enhancing the effectiveness of sulfuric acid leaching of sandstone uranium ores and has broad application prospects.

TEAK SEEDS (Tectona grandis L.f.) GERMINATION BASED ON DIFFERENT CONCENTRATION AND SOAKING TIME LENGTH USING SULFURIC ACID SOLUTION (H2SO4)

Teak (Tectona grandis L.f.) is a plant that produces raw materials for the wood industry, which is very popular due to its high quality and selling value. Procurement of teak seeds can be done in two ways: generatively and vegetatively. One problem in cultivating this plant is the inhibition of seed germination due to dormancy. Teak roots experience physical inactivity, namely tough skin. One technique that can be used to break seed dormancy is through chemical treatment. This study aims to determine the concentration of sulfuric acid (H2SO4) and the appropriate soaking time to break the teak seeds dormancy. This research was conducted for two months in the Permanent Nursery of the Department of Forestry, State Agricultural Polytechnic of Kupang, from 15 November 2022 until 15 January 2023. This study used a Completely Randomized Design (CRD) with two factors. The first factor was the concentration of a sulfuric acid solution (control: K0, 75% H2SO4: K1, 80% H2SO4: K2, and 85% H2SO4: K3). The second factor was the soaking time (T1: 45 minutes, T2: 50 minutes, and T3: 55 minutes). The two factors was combined to produce 12 treatment combinations as a whole. Each treatment was repeated three times and used ten seeds, so the total seeds used were 360 seeds. The results showed that there was an interaction between the concentration of sulfuric acid solution (H2SO4) with soaking time length, where the combination of 75% sulfuric acid (H2SO4) concentration and 45 minutes of soaking time gave higher results than other treatments, so it can be said that this combination is better at breaking teak seed dormancy.

Life Cycle Assessment of Cobalt Catalyst Production and Recycling

Catalysts with an active phase of cobalt are crucial for Fischer–Tropsch synthesis (FTS), yet the environmental impacts of the catalyst production and the recycling of the spent catalyst remain largely unknown. The goal of this study was to evaluate the impacts of both catalyst production as well as the recycling of spent catalyst as cobalt hydroxide, cobalt sulfate, or cobalt carbonate. Life cycle assessment (LCA) was used to quantify the environmental impacts of the studied processes. The life cycle inventory (LCI) was gathered based on the mass and energy balances of process simulations built on information available in the literature. The results show that compared to primary production of equivalent products, all studied recycling processes for spent catalyst decrease the environmental impacts by more than 50% in all investigated impact categories. For example, the global warming potential (GWP) of cobalt recovery from spent FTS catalyst as cobalt sulfate was 1.7 kg CO2-eq./kg CoSO4whereas the corresponding GWP for primary production was 4 kg CO2-eq./kg CoSO4. The process hotspots of recycling were found to be the production of the chemicals consumed, particularly sodium hydroxide and sulfuric acid, which together contributed between 64 and 95% of the total environmental impacts. LCAs on FTS have included the consumption of cobalt catalyst in the LCI using various approximations. The impacts calculated for the production of cobalt catalyst in this study were found to be markedly higher. The largest contributors included the production of materials for the precursor and support, as well as NOx emissions and consumption of nitric acid.Graphical

Fabrication of tetra‐n‐butylammonium hydrogen sulfate‐based poly(lactic acid)‐poly(ethylene glycol) composite electrospun wound dressing

AbstractIn this study, poly(lactic acid)‐poly(ethylene glycol)‐tetra‐n‐butylammonium hydrogen sulfate (PLA‐PEG‐HS) electrospun mats were fabricated by electrospinning as effective wound dressings against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), which are the most prevalent species of gram‐positive and gram‐negative bacteria, respectively. PLA is a polymer with high biocompatibility and biodegradability, but its structure is fragile. Therefore, we aimed to improve its structural properties using PEG as a plasticizer and to provide antibacterial properties with HS salt. The nanofibers characterized using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), and drying time tests. The addition of HS eliminated the beads in the PLA‐PEG nanofiber and improved the homogeneity of the fiber distribution. Concerning this result, when the liquid absorption capacity (LAC) test was evaluated, PLA‐PEG‐HS nanofiber production was achieved with the highest rate of 480.95%. The thermal properties of nanofibers increased with the addition of HS. Cytotoxicity test results of PLA‐PEG‐HS wound dressings showed high cell viability of 129.05% in L292 mouse fibroblast cells at the end of the 24th hour. PLA‐PEG‐HS nanofibers with 99.99% antibacterial activity against tow bacteria. Considering the modern wound dressing requirements, antibacterial wound dressing production has been successfully achieved.

Study of the Production of Wet-processing Phosphoric Acid by Clinker Method on Base of Mineralized Mass

The article presents the results of the study of extractive phosphoric acid extraction processes from the mineralized mass (MM) - mineralized mass (MM) produced during the thermal processing of Central Kyzylkum (CK) phosphorite. Effects of sulfuric acid concentration on the quality parameters of the obtained wet-processing phosphoric acid (WPPA), processes of WPPA extraction through different concentrations of phosphoric acid solution from phosphoric acid-gypsum porridge were studied. The optimal parameters of these processes have been determined. In the composition of WPPA obtained in acceptable parameters 19,30-19,59% Р2О5, 0,08-0,09% F will be. Filtration rates of phosphatic-acid-gypsum porridges during extraction with different concentrations of WPPA are equal to 1096-1192 kg/m2·h. It was also determined that the main composition of the resulting phosphogypsum is as follows: 2,44-2,59% Р2О5total (t.)., 29,93-30,09% CaOtotal (t.), 41,29-41,50% SO3 and 1,16-1,21% F.

Veolia to sell sulfuric acid business

Veolia to sell sulfuric acid business

Consolidated bioprocessing of lignocellulosic wastes in Northwest China for D-glucaric acid production by an artificial microbial consortium.

D-glucaric acid is a platform chemical of great importance and the consolidated bioprocessing (CBP) of lignocellulose by the microbial consortium of Trichoderma reesei C10 and Saccharomyces cerevisiae LGA-1C3S2 features prospects in biomanufacturing it. Here we compared some representative lignocelluloses in Northwest China including corn stover, wheat straw and switchgrass, and the leading pretreatments including steam explosion, subcritical water pretreatment, sodium hydroxide pretreatment, aqueous ammonia pretreatment, lime pretreatment, and diluted sulfuric acid pretreatment. It was found that sodium hydroxide pretreated switchgrass (SHPSG) was the best substrate for D-glucaric acid production, resulting in the highest D-glucaric acid titers, 11.69 ± 0.73g/L in shake flask and 15.71 ± 0.80g/L in 10L airlift fermenter, respectively. To the best of our knowledge, this is the highest D-glucaric acid production titer from lignocellulosic biomass. This work offers a paradigm of producing low-cost D-glucaric acid for low-carbon polyethylene 2,5-furandicarboxylate (PEF) and a reference on developing biorefinery in Northwest China.

Role of electrode temperature in anodic growth of sulfuric acid alumina films

Role of electrode temperature in anodic growth of sulfuric acid alumina films

Leveraging organic acids in bipolar membrane electrodialysis (BPMED) can enhance ammonia recovery from scrubber effluents

While air stripping combined with acid scrubbing remains a competitive technology for the removal and recovery of ammonia from wastewater streams, its use of strong acids is concerning. Organic acids offer promising alternatives to strong acids like sulphuric acid, but their application remains limited due to high cost. This study proposes an integration of air stripping and organic acid scrubbing with bipolar membrane electrodialysis (BPMED) to regenerate the organic acids. We compared the energy consumption and current efficiency of BPMED in recovering dissolved ammonia and regenerating sulphuric, citric, and maleic acids from synthetic scrubber effluents. Current efficiency was lower when regenerating sulphuric acid (22 %) compared to citric (47 %) and maleic acid (37 %), attributable to the competitive proton transport over ammonium across the cation exchange membrane. Organic salts functioned as buffers, reducing the concentration of free protons, resulting in higher ammonium removal efficiencies with citrate (75 %) and malate (68 %), compared to sulphate (29 %). Consequently, the energy consumption of the BPMED decreased by 54 % and 35 % while regenerating citric and maleic acids, respectively, compared to sulfuric acid. Membrane characterisation experiments showed that the electrical conductivity ranking, ammonium citrate > ammonium malate > ammonium sulphate, was mirrored by the energy consumption (kWh/kg-N recovered) ranking, ammonium sulphate (15.6) < ammonium malate (10.2) < ammonium citrate (7.2), while the permselectivity ranking, ammonium sulphate > ammonium citrate > ammonium malate, aligned with calculated charge densities. This work demonstrates the potential of combining organic acid scrubbers with BPMED for ammonium recovery from wastewater effluents with minimum chemical input.

A Comparative Study of the Influence of Soil and Non-Soil Factors on Seed Germination of Edible Salt-Tolerant Species

Cultivating edible salt-tolerant plants (halophytes) for human consumption is increasingly important due to climate change and soil salinization, and offers sustainable agricultural solutions. Optimizing seed germination, the crucial initial stage of crop growth, is essential for enhancing crop production. This study aimed to optimize the germination of edible halophytes under greenhouse conditions, focusing on select soil (salinity and substrate) and non-soil-related factors (chemical and mechanical treatments). The target species were selected for their commercial value and included Mesembryanthemum crystallinum L. (crystalline iceplant), Salicornia ramosissima J. Woods (sea asparagus), Medicago marina L. (sea medick), Ammophila arenaria (L.) Link (European beachgrass), Portulaca oleracea L. (common purslane), and Atriplex halimus L. (Mediterranean saltbush). Salinity negatively impacted germination rates (GRs) and delayed mean germination time (MGT) across species. P. oleracea had the highest GR (95.6%) in coco peat under freshwater irrigation, and the shortest MGT (5.2 days). A. halimus did not germinate under the tested conditions. Scarification with sulfuric acid improved the GR of M. marina by 42.2%, while scarification with ultrasounds improved the GR of A. arenaria by 35.5%. Our results indicate that the choice of substrate and the application of specific treatments like scarification can significantly improve the germination of certain halophyte species under variable saline conditions.

Indole derivatives efficacy and kinetics for inhibiting carbon steel corrosion in sulfuric acid media

The global prevalence of metal corrosion is a significant challenge due to its detrimental effect. Environmentally friendly and non-hazardous alternatives for harmful and poisonous synthetic corrosion inhibitors are urgently necessary due to increasing environmental concerns and regulations prohibiting their application. In this study, indole molecules were employed as carbon steel corrosion inhibitors in acidic conditions. Gravimetrical and scanning electronic microscope (SEM) analysis was used in a preliminary investigation of indole as an organic inhibitor. The results revealed that adding indole to carbon steel before exposing it to sulfuric acid slowed and induced resistance to corrosion. The indole affixed themselves to the steel carbon surfaces, producing a barrier/protection for carbon steel. The efficacy of the indole in preventing corrosion was determined through the weight loss method. Temperature and inhibitory concentration effects on inhibition effectiveness under varying parameters were also reported. The temperatures employed were between 298 K and 328 K, while the inhibitor concentrations ranged from 1.2 × 10−3 M to 7.6 × 10−3 M, and both parameters significantly influenced corrosion inhibition effectiveness. The inhibitory mixture attained optimum efficacy in inhibiting corrosion, at 81 %, when the lowest and highest respective temperature and concentration were applied. The kinetic analysis was conducted under a range of temperatures to determine the reaction mechanisms of the inhibitor. The thermal adsorption isotherm of the inhibitor indicated that the surface adhered to Langmuir's adsorption isotherm. Additionally, investigations on corrosion and inhibition using the electrochemical impedance spectroscopy method (EIS) were conducted. This study can provide in-depth knowledge for advancing inhibitory science and engineering to enhance corrosion resistance in acidic media.

Utilization of banana peel waste for the production of bioethanol and other high-value-added compounds

Bananas (Musa sp.) are one of the most produced crops worldwide, surpassing 100 million tons per year, and considering that approximately 30 % of their weight consists of peels, the annual generation of these residues is significant. Banana residues are rich in nutrients; nowadays, they are all disposed of in landfills. As a novelty, this work showed that it could be used for other things, such as alcohol, D-Limonene, and citric acid production. This study characterized the biomass, optimized pretreatment, and enzymatic hydrolysis and evaluated the fermentation process using this biomass, using the central composite design (CCD) methodology. The planning variables included sulfuric acid (H2SO4) concentration, banana peel waste mass in the pretreatment stage, and commercial cellulase enzyme (Sigma-Aldrich) concentration in the enzymatic hydrolysis stage. The responses quantified were sugars, ethanol, and acids using high-performance liquid chromatography, and the D-Limonene content was determined on a gas chromatograph coupled to a mass spectrometer. The highest yield of total reducing sugars found after enzymatic hydrolysis was 11.88 g/L, while the ethanol yield was 1.37 g/L. In the recovery of D-Limonene, the obtained value was 0.56 mg/g. The values of fermentable sugars confirm banana peel waste as a potential biomass for biorefinery processes. Furthermore, the possibility of an integrated D-Limonene recovery is essential in obtaining bioproducts. In this sense, it can be concluded that utilizing these residues is promising in reducing environmental issues and valorizing food waste.

A novel and clean utilization of flue gas desulfurization ash coupled with converter sludge to produce calcium ferrate

To address the environmental pollution from industrial wastes like desulfurization ash (DA) and converter sludge(CS), this study introduces a novel method for synthesizing calcium ferrate. This method involves reacting converter sludge with desulfurization ash at high temperatures, facilitating the concurrent elimination of toxic elements. The solid byproduct is suitable as a sintered ore additive, while the gaseous SO2 serves as a precursor for sulfuric acid production. Additionally, the metal-rich secondary dust offers a source for valuable metal recovery. This research employs simulation software (FactSage 8.1) and thermal analysis to explore the high-temperature reaction dynamics of converter sludge and desulfurization ash. Subsequent in-situ experiments and coupled high-temperature tube furnace-infrared flue gas analysis further elucidated the phase transitions, morphology changes, flue gas emissions, and migration of harmful elements (e.g., S, K, Na, Pb, Zn). Analysis using the Predom dominant zone module calculation indicates that low SO2 concentration and reduced oxygen levels promote the stability of Ca2Fe2O5. Infrared flue gas analysis reveals high concentrations of CO2 and SO2. Sulfur removal rates rose from 62.15 % to 98.48 % between 800 °C and 1100 °C. Removal efficiencies for alkali and heavy metals, namely K, Na, Pb, and Zn, improved significantly, reaching 99.95 %, 99.49 %, 99.71 %, and 86.7 % respectively. At 1100 °C under an N2 atmosphere, the main reaction products from Flue Gas desulfurization ash (FGDA) and converter sludge were CaFe3O5 and Ca2Fe2O5. This study’s comprehensive analysis of synthesizing calcium ferrate from Flue Gas desulfurization ash and converter sludge introduces a novel waste utilization method, offering substantial environmental and economic advantages.

In-depth insights into transformation mechanism of synthetic saponite to amorphous silica under acid attack

Amorphous mesoporous materials derived from synthetic saponite (Sap) by acid treatment have been used in catalysis for several decades. Uncovering the transformation process of Sap from layered to amorphous structure under acid attack is beneficial to optimize the structure of Sap-derived mesoporous materials, yet such transformation process remains unclear. Herein, a magnesium-Sap was synthesized by hydrothermal method and then treated with sulfuric acid. By studying the changes in phase composition, morphology, chemical state of elements and surface area of the synthetic Sap after acid attack, a specified transformation mechanism of synthetic Sap to amorphous silica is clarified. The experimental results indicate that after leaching of Mg and Al cations from the Mg/AlO6 octahedral sheets of Sap during acid attack, the retained SiO4 tetrahedral sheets of Sap were transformed into amorphous short-range ordered silica phases and nanoscrolls with pseudohexagonal side pores. The transformation process of synthetic Sap under acid attack can be divided into leaching of metal ions from octahedral sheets of Sap to form layered silica particles, splitting and crimping of surface nano-silica layers from the formed silica particles, and completely amorphous transformation. The distortion of SiO bonds in SiO4 tetrahedral sheets during acid attack might be the driving force for such transformation. This work provides specific transformation process of synthetic Sap under acid attack which is conductive to the controllable preparation of acid-treated Sap derivates, and has certain significance for understanding of structural transformation of clay minerals with MgO6 octahedral structure.