Quicklime Research Articles

The use of quicklime for soil thawing in pile foundation setting

Due to the fact that in the winter period, which in the Northern regions of the Republic of Kazakhstan lasts up to 6 months, and in the Southern regions – up to 4 months, construction companies are forced to suspend construction and installation works on the foundations. As a result, the total duration of construction of facilities increases, which leads to additional financial expenses. Therefore, new technological solutions are needed for the construction of foundations in winter, to ensure the continuity of construction and installation work. The purpose of the study is to develop a formula of chemical reagents for thawing and protection from the freezing of seasonally frozen soil in places where pile foundations are driven in winter conditions. For the study, a three-component mixture of chemical reagents of the following composition, wt.%, was selected: quick lime (CaO) – 75, calcium chloride (CaCl) – 20, sodium chloride (NaCl) – 5. The choice of the specified composition is determined by taking into account their specific chemical properties and special reactions when interacting with water and frozen soil. The active components of quick lime (CaO) are converted to Ca(OH)2 when interacting with a wet environment or water. This process is accompanied by spontaneous heat release. In the course of the study, a new composition of a chemical reagent based on quick lime was developed for local thawing and protection from the freezing of seasonally frozen clay soil in the areas of driving pile foundations. This composition has advantages in terms of reducing energy costs for thawing seasonally frozen soil, since when interacting with water, the proposed chemical reagent spontaneously releases heat (t = 100oC) and does not cool down for a long time despite the negative ambient temperature of the air.

Assessment of lime‐conditioned dairy manure fine solids captured using dissolved air flotation for fertilization in horticulture

Dissolved air flotation (DAF) has shown potential to substantially improve phosphorus (P) mass balance on dairy farms by capturing P associated with fine solids from liquid manure, enabling new management options. However, at<25% total solids, further dewatering is necessary to facilitate export of recovered fine solids off farm for use in bagged or bulk products. Physical conditioners such as quicklime (QL) and lime kiln dust (LKD) are commonly used to enhance mechanical dewatering of biosolids, but their effect on the properties and fertilization value of DAF-captured manure fine solids has not been documented. We generated plant foods using DAF-captured dairy manure fine solids conditioned with 3, 4.5, and 6% m/m QL or LKD and dewatered using a benchtop press for comparison with thermally dried fine solids. Tomato (Solanum lycopersicum L.) seedlings were grown in a soilless substrate amended with 6% v/v plant food and in an unamended control. Thermally dried and LKD plant foods produced significantly greater seedling biomass than QL plant foods and the unamended control. Quicklime- and LKD-conditioned fine solids contained approximately 30× and 10× less water-extractable P than thermally dried fine solids, respectively, likely due to precipitation of Ca-P minerals. The elevated pH (≥10) of the lime-conditioned fine solids could have also suppressed plant growth. These effects limit horticultural applications but could be beneficial in agricultural field settings where slow-release P is desirable. Research beyond this preliminary assessment is needed to determine the practicality and sustainability of the approach along with longer-term nutrient bioavailability.

Comparison between CaO- and MgO-activated ground granulated blast-furnace slag (GGBS) for stabilization/solidification of Zn-contaminated clay slurry

Stabilization/solidification (S/S) is a low-cost and effective remedial technique for dredged contaminated sediments. Quick lime (CaO)-activated and reactive magnesia (MgO)-activated ground granulated blast furnace slag (GGBS) are effective and low-carbon S/S binders. However, the existence of metals, especially Zn, in contaminated sediments, may hinder the hydration of GGBS. This study compared the performance and mechanisms of CaO-GGBS, MgO-GGBS and ordinary Portland cement (OPC) for the treatment of Zn-contaminated clay slurry using unconfined compressive strength (UCS) test, one-stage batch leaching test, and mineralogical and thermal analyses. The results showed that the application of the MgO-GGBS (GGBS dosage of 10 % and MgO of 0 %–3 % (of dry clay by mass)) had positive effects on the mechanical strength and Zn immobilization of the contaminated clay slurry while the CaO-GGBS affected negatively and the situation became even worse at a higher CaO dosage (0 %–1.5 % of dry clay by mass). In comparison with OPC, the application of MgO-GGBS produced higher mechanical strength and that for CaO-GGBS was the lowest. The Zn leaching difference depends on initial Zn concentrations. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) results showed that a retarder, calcium zinc hydroxide, formed in the immobilization process when adding the CaO-GGBS binder, hindering the GGBS hydration and further leading to inferior strength and higher Zn leachability. The clay slurry treated by the MgO-GGBS binder was found to have a higher calcium silicate hydrate content which explained its high strength and low leachability.

The Improvement of Engineering Properties of Expansive Soil using Waste Glass Powder (WGP) and Quick Lime

This study was carried out with an intention to observe any sign of improvement of expansive clayey soil due to the addition of Waste Glass Powder (WGP) with it. In this laboratory work clayey (BC) type soil has been chosen. The reason behind choosing clay is that it has many problems. The main problem is that it undergoes consolidation settlement due to the application of long-term loading. Another problem is it shrinks significantly if it is dried and expands significantly, if it absorbs moisture than exerts much pressure on the substructure. Quick Lime and Waste Glass powder is chosen to check the improvement because waste glass powder is cohesionless material and also contains silica, lime etc. Addition of cohesionless material to the cohesive soil means it will lesser the consolidation settlement and expansive nature of soil and Lime provides binding property. To investigate the traditional methods of analysing, the effect of additives on soil has been adopted i.e., conducting several tests of untreated soil and soil treated with waste glass and lime with varying percentage and then comparing the results obtained. The tests that were carried out in this study are Compaction test (Proctor test), Consolidation test (unconfined compression test). MDD and Unconfined compressive strength increases with the addition of glass powder and lime with oven dried expansive soil.

PENGARUH PENAMBAHAN KAPUR TOHOR TERHADAP SIFAT MEKANIS BATA RINGAN

&lt;p align="center"&gt;&lt;strong&gt;Abstract&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Light brick is an alternative material in the construction sector that has an efficiency value, in addition to being lighter than conventional bricks for building loads, lightweight bricks also reduce the use of materials during construction. One of the uses of light bricks is on walls. This is because the walls contribute to the heavy load on the building structure. Along with the development of the use of light bricks, research was carried out on light bricks with quick lime mixture as a substitute for part of the cement on light bricks which refers to the mechanical properties of light bricks which include free compressive strength testing, while the variation of the mixture used is 5%, 10%, 15%, and 20% of the volume of cement used. The results of the compressive strength of light bricks at the age of 28 days, respectively, the variation of the lime mixture 5%, 10%, 15%, and 20% obtained compressive strength of 0.96 Mpa, 0.81 Mpa, 0.43 Mpa, and 0.32 Mpa where compressive strength The maximum is obtained in the lime mixture as much as 5%, is 0.96 Mpa.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Novel calcium carbonate filler for cellulose industry

AbstractPrecipitated calcium carbonate (PCC) filler is used in many industrial products like constructions, plastics, pharmaceutics, etc. In this study producing cationic precipitated calcium carbonate filler for paper industry was investigated. Hence, a cationic polyacrylamide and cationic corn starch have been incorporated into the PCC particles to produce a modified filler with cationic structure and improved hydrogen bonding ability with cellulose fibers. According to the FESEM and XRD results, cubic-like fillers with prominently calcite polymorph and a slight amount of aragonite were successfully produced from the industrial burnt lime using carbonation process. The presence of organic substances in the structure of the modified samples was confirmed by FT-IR analysis. Besides, based on the FESEM results, filler morphology and particle size could be affected by the polymer content. In conclusion, introducing cationic groups to mineral fillers could be considered as a possible strategy to overcome some detrimental effects of using mineral fillers in paper products.

Bacteria fixing CO2 to enhance the volume stability of ground steel slag powder as a component of cement-based materials aiming at clean production

Steel slag is a by-product in the process of steel manufacture. It has caused huge environmental pressure. The use of steel slag as the admixture of cement-based materials is an effective way to enhance clean production. But the poor volume stability caused by dead burned lime and periclase in steel slag is a crucial factor restricting its utilization. Some research has shown that carbonization could convert dead burned lime and periclase into carbonate. But the carbonization rate and carbonization degree were low. The objective of this paper is to adopt Bacillus Mucilaginosus (BM) to absorb carbon dioxide to promote the carbonization of dead burned lime and periclase, thereby enhancing steel slag utilization in cement-based materials. The effects of BM on the carbonization rate and degree of dead burned lime and periclase were studied by conducting experiments; the influence of BM on the stability of steel slag mortar with different particle sizes was studied. The results show that BM can reduce the apparent activation energy of the carbonization reaction of dead burnt lime and periclase, and increase the reaction rate and maximum reactivity. MIP (Mercury Intrusion Porosimetry) analysis found that steel slag mortar specimen with BM had a lower porosity than that without BM. The autoclaved linear expansion rate of the steel slag mortar specimen with BM can meet standard requirements while that without BM cannot. It is indicated that the addition of BM can effectively promote the carbonization of dead burned lime and periclase in steel slag and solve the problem of poor volume stability of cement-based materials caused by steel slag. This research helps to improve the utilization of steel slag as an alternative binder to cement and alleviates the environmental pressure caused by the storage of waste steel slag.

Shedding light onto the spectra of lime—Part 2: Raman spectra of Ca and Mg carbonates and the role of d‐block element luminescence

AbstractWe previously described the observation of a characteristic narrowband red luminescence emission of burnt lime (CaO), whose reason was unknown so far. This study presents Raman spectra of Mg5(CO3)4(OH)2·4H2O, Mg5(CO3)4(OH)2, MgCO3, CaMgCO3 and CaCO3 (in limestone powder) as well as luminescence spectra of their calcination products. Comparison of the latter revealed MgO:Cr3+ as the source of the red lime luminescence in all studied samples, containing magnesium oxide as major component, minor component or trace. Spectral characteristics and theoretical background of the luminescence emission of d‐block elements integrated in crystal lattices are discussed with the aim of sharpening the awareness for this effect in the Raman community and promoting its application in materials analysis. The latter is demonstrated by the Raman microspectroscopic imaging of the distributions of both Raman‐active and Raman‐inactive phases in clinker remnants in a 19th‐century meso Portland cement mortar sample, which contain relatively high amounts of free lime detected in the form of both luminescing CaO and Raman‐scattering Ca(OH)2, owing to exposure of the surface of the thin section to humid air. A combination of light and Raman spectroscopy revealed a calcium–magnesium–iron sulphide phase, indicating sulphurous raw materials and/or solid fuels employed in the calcination process, which in contrast to previously described morphologies of sulphides in cement clinker form extensive greenish black layers on free lime crystals.

On the possibility of autoclave desiliconization of ilmenite-leucoxene concentrates using lime milk

This article presents the results of studies on the autoclave desilicization of silicon-titanium concentrates of the Pizhemskoye field. Leaching was carried out using burnt lime as a reagent in the presence of the initiator NaOH. The work was carried out on two types of concentrate-pseudorutyl (siliceous-ilmenite) and leucoxene concentrate, which differ in the content of SiO2 (14,03 and 36,8%, respectively) and Fe2O3 (21,6 and 1,1%, respectively). The process was based on the selective binding of silica to calcium hydrometasilicate, which, upon subsequent calcination at 1050 °C, crystallizes into β-wollastonite.

Binding effects of organic and inorganic powder on shear and tensile strengths of granular material packing

In this study, the effects of quick lime (QL), calcite, and sodium lignosulfonate (SL) powders combined with liquid on granular system were compared. Different loading stresses were used to compare their shear and tensile characteristics. Glass beads (400–600 µm in size) and varying powder-to-liquid contents (from 0% to 5% in mass) as the binder in mixture were used to investigate their shear behavior and bulk density. Results showed that the shear strength was improved for all tested powder binders with their increased content in mixture. QL and calcite powders were weak when the liquid content was large (4–5%). Meanwhile, SL powder sufficiently controlled liquid and improved cohesion-related forces required to form and maintain granular bed stability. It also exhibited higher tensile strength than the other powders. Similar to SL powder, QL powder maintained significant tensile strength. The cohesion was enhanced and varied in the range of 0.17–1.46 kPa for QL powder and 0.10–1.08 kPa for calcite powder. By contrast, SL powder resulted in a high cohesion of 0.39–1.59 kPa for overall contents. The measured bulk density decreased to a certain extent and then increased for all powder binders with liquid content.

New process to obtain unslaked lime through microwave hybrid heating and its fluid dynamics computational modeling

This study aimed to analyze the advantages of limestone calcination through a conventional microwave heating technique. For such a purpose, the microwave was merged by hybrid heating and a refractory ceramic internally coated with copper oxide was used with a conventional muffle furnace. It has also been analyzed the behavior of calcining limestone with different masses and variations in retention time using a muffle furnace and microwaves, both with and without using the refractory ceramic. Afterwards, the process has been modeled so as to analyze temperature versus retention time. As a result, calcination using a microwave susceptor with the refractory ceramic substance proved to be a process that takes 35% less time than conventional methods. Furthermore, there has been a reduction in 66.1% of energy expenditure. It was also observed that the new procedure offers advantages in reduced greenhouse gases emissions on account of the release of only a single substance, ease of air treatment in industrial environments and being a more economically viable process for limestone calcination, which can be further utilized by companies belonging to such a sector. Its patent deposit number BR 202018073002-4 U2 in INPI.

Enhancement of the quick lime‐based solidification/stabilization of oily wastes using modified clay

AbstractBACKGROUNDThis research investigated the solidification/stabilization process (S/S) efficiency of contaminated soil by total petroleum hydrocarbons (TPH) in the waste of a used oil treatment plant using quick lime (QL) as a binder and modified clay (MC) as an additive. Several objectives were considered, including reducing the mobility and leaching of TPH, investigating the effect of MC on the QL hydration process in the presence of organic matter, the possibility of S/S waste reuse, and estimating the S/S cost for the optimum mixture.RESULTSThe unconfined compressive strength (UCS) increased about 45% by increasing 25% of QL without MC, but these S/S wastes did not satisfy the waste reuse standards. Additionally, adding any ratio of MC to samples containing QL increased UCS significantly. The UCS of all samples at the age of 28 days with different QL and MC proportions obtained more than 350 kPa (the minimum UCS required for S/S waste disposal in the landfill). Moreover, the toxicity characteristic leaching procedure (TCLP) test revealed that TPH leaching of contaminated soil was 3.8 mg L−1 but adding only 15% of QL could reduce TPH leaching to less than 1 mg L−1, which is the maximum allowable TPH leaching.CONCLUSIONThe combination of QL and MC decreased TPH leaching, significantly. The scanning electron microscopy analysis also showed that QL hydration was improved by increasing the amount of MC. Finally, a sample with 35% QL and 15% MC was selected as an optimum sample due to its cost of $80.5/ton. © 2021 Society of Chemical Industry (SCI).

Emission reduction through preconstruction and utilization of alternative materials in infrastructure projects

Construction have a significant impact on the amount of emitted green-house gas (GHG) and a potential to cut emissions is quite substantial. In this article, possibilities provided by preconstruction activities and utilization of alternative materials are discussed. Preconstruction means actions to be taken in advance when soils in the construction area are too soft. These actions may be e.g. deep mixing, replacement or preloading. Considering that constructed subgrades, ground improvement and some other earth works required for the infrastructure project can be very energy-intensive, emissions can be reduced substantially only if preconstruction options, areal mass balance and potentiality of alternative materials are identified early enough. Examined case studies also focus on possibilities to reduce emissions related to certain materials e.g. deep mixing binding agents. In deep mixing, blend of cement and quick lime is the most traditional binder component. Therefore, reducing the amount of cement + lime and selecting the cement type have a great impact on CO2 emissions. Cement amount can be reduced by alternative materials such as fly ash, blast furnace slag or gypsum. Possibilities to reduce CO2 emissions were studied in various infrastructure projects and reflected to climate strategies. The studies were focused on areas and operations where changes were possible such as transportation, construction materials or subgrade construction methods. This article describes the case studies related to construction of various infrastructure projects and identified possibilities to reduce emissions.

Empirical method for predicting time-dependent strength and resilient modulus of chemically treated soil

Development of unconfined compression strength (UCS) and resilient modulus (MR) of chemically treated soil was investigated. Test samples were cured at room temperature from 1 to 28 days. Numerous other physical and index properties were used to characterize the treated and untreated soils. The work involved 18 different combinations of soils and chemical stabilizers including, cement kiln dust (CKD), Class C fly ash (CFA), and quick lime (CaO). Results revealed trends associated with additive and soil characteristics used to develop practical correlations for predicting development of UCS and MR as a function of curing time and basic soil properties.

Evolution of physicochemical properties of quick lime at converter-smelting temperature

Abstract The volume stability caused by the hydration of f-CaO is one of the main obstacles to the comprehensive utilization of steel-making slag. In view of the f-CaO produced by incomplete dissolution of lime, it is necessary to strengthen the dissolution behavior of lime in the converter process. The reactivity of lime determines the dissolution efficiency and is closely related to its microstructure. The experimental results show that the reactivity and porosity of quick lime decrease and the average diameter of pore increases with an increase in temperature. The CaO crystals gradually grow up under the action of grain boundary migration. When the temperature increased from 1,350 to 1,600°C, the lime reactivity decreased from 237.60 to 40.60 mL, the porosity decreased from 30.55 to 15.91%, the average pore diameter increased from 159.10 to 1471.80 nm, and the average CaO particle size increased from 0.33 to 9.61 µm. The results indicate that reactivity is decreased because of the deformation and growth of CaO crystals and the decrease in porosity in reactive lime. This will cause an obstacle to the dissolution of lime and is not conducive to the control of f-CaO in slag.

Effect of Pozzolana and Lime on Expansive Soil Properties

This study investigates the effect of pozzolana and quick lime as stabilizer materials on expansive soil properties. Disturbed soil sample was collected from Al-Qadarif city in east of Sudan. The basic properties, swelling and strength of the soil were measured. The soil shows very weak strength and very high swelling potential. Mineralogical analysis tests were conducted to the soil using XRD tests. The soil contains significant amount of montmorillonite mineral (86%). Laboratory tests were undertaken on soil stabilized with varying percentage of pozzolana only (0, 5, 10, 15, 20, and 30%) and combination of pozzolana with constant content of quick lime (5%). Compaction, California Bearing Ratio (CBR), free swell, swell present and swelling pressure tests were performed on natural and treated soil. The pozzolana was obtained from Jebal Meidob and the lime obtained from local kilns in Kassala. The results showed that the treatment of expansive soil by combination of pozzolana and quick lime reduced soil swelling coupled with significant increase on soil strength. While the use of pozzolana only has marginal effective. It could be concluded that stabilization of expansive soil by pozzolana-lime admixture is successful.

Freeze-thaw resistance of eco-material stabilized loess

In the Loess Plateau in Northern China, repeated freeze-thaw (FT) cycles deteriorate the strength and structure of loess as a foundation soil, resulting in the instability or failure of supporting structure. Lignosulfonate is an eco-material, utilized as an effective and nontraditional stabilizer to improve the engineering properties of metastable soils. A series of laboratory tests, including unconfined compression tests, cyclic loading-unloading tests and scanning electron microscopy, on calcium lignosulfonate (CL)- and sodium lignosulfonate (SL)-stabilized loess were performed to investigate the stabilization effect, deterioration mechanisms of the FT cycles, and the resistance to FT cycles. Two traditional stabilizers, quicklime (QL) and sodium silicate (SS), were selected, and the engineering properties of QL- and SS-stabilized loess were compared with those of CL- and SL-stabilized loess. The results showed that the strength values of CL- and SL-stabilized loess specimens decreased by 34.2% and 50% respectively, after 20 FT cycles, whereas those of the traditionally SS- and QL- stabilized specimens decreased by 85.3% and 82.87%, respectively. The elastic moduli of SL- and QL-stabilized loess specimens decreased by 22.1% and 92.0%, respectively. The mean energy dissipations of nontraditionally treated specimens also decreased significantly less than those of traditionally treated specimens. Overall, the results showed CL and SL had better stabilization effects on engineering properties of loess than QL and SS, and their stabilized loess specimens exhibited stronger resistance to FT cycles. The study findings demonstrated the significant potential of lignosulfonate for extensive application in cold loess areas.

Three-Dimensional Printing of Natural Materials Involving Loess-Based Composite Materials Designed for Ecofriendly Applications.

In this work, loess-based materials were designed based on a multicomponent composite materials system for ecofriendly natural three-dimensional (3D) printing involving quick lime, gypsum, and water. The 3D printing process was monitored as a function of gypsum content; in terms of mechanical strength and electrical resistance, in the cube-shaped bulk form. After initial optimization, the 3D printing composition was refined to provide improved printability in a 3D printing system. The optimal 3D fabrication allowed for reproducible printing of rectangular columns and cubes. The development of 3D printing materials was scrutinized using a multitude of physicochemical probing tools, including X-ray diffraction for phase identification, impedance spectroscopy to monitor setting behaviors, and mercury intrusion porosimetry to extract the pore structure of loess-based composite materials. Additionally, the setting behavior in the loess-based composite materials was analyzed by investigating the formation of gypsum hydrates induced by chemical reaction between quick lime and water. This setting reaction provides reasonable mechanical strength that is sufficient to print loess-based pastes via 3D printing. Such mechanical strength allows utilization of robotic 3D printing applications that can be used to fabricate ecofriendly structures.

Comparison of maceration techniques for retrieval of bones

Introduction: Learning osteology is an essential part of anatomy curriculum. However, recently, there has been a scarcity in the availability of bones for teaching in India. The present study was conducted to compare four different maceration techniques and find the most suitable method to procure bones from an embalmed cadaver. The present study was conducted on dissected human cadavers made available from the department of anatomy. Material and Methods: For the first three methods, after dissection, the cadavers were buried in the burial section of the department for 2 years. The bones were washed after excavation. In the first method, detergent was used; in the second, quick lime was used; and in the third, hydrogen peroxide was used. In the fourth method, parts were not buried. The dissected parts were defleshed manually. The bones were freed from the joint. A paste was made using baking soda and 30% hydrogen peroxide. This was applied and bones were kept covered for 24 h. All four methods were compared. Results: Based on time required to macerate, ease of soft-tissue removal and complete procurement with minimal damage, the method using 30% H2O2 was the best. For smaller specimens, the new method of applying a paste of baking soda and H2O2 was very effective. The time consumed was very less. Discussion and Conclusion: Maceration using 30% H2O2 gave the best result. New method tried is time-saving and useful for small specimens. Soft tissue was removed easily with no/minimal damage to the bone.

Strength enhancement of Clayey Sand subgrade using lime and rice husk ash

In recent times, enormous quantities of industrial wastes like silica fume, slag, fly ash, cynosphere, rice husk ash (RHA) etc. are produced all over the world. This industrial wastes are dumped in open landfills leading to land wastage and causing environmental pollution. If these wastes could be utilized as construction materials, then quantity of waste that is being dumped could be reduced leading to preservation of environment. Thus the objective of the current project was to utilize RHA along with quick lime as an admixture with Clayey Sand subgrade soil to determine the effect of quick lime and RHA on its strength characteristics after 3 days curing period. Lime was added to Clayey Sand to facilitate proper bonding between RHA and the soil. Based on the test results, 4% lime with 20% RHA was found to be optimal percentage of admixture for Clayey Sand for which maximum unconfined compression strength (UCS) and soaked CBR strength was attained after 3 days curing.