Fine Lime Research Articles

Multi-analytical approach to the mural painting from an ancient tomb of Ming Dynasty in Jiyuan, China: Characterization of materials and techniques

The pigments, surface deposition, preparatory layer and support from a mural painting tomb of Ming Dynasty (1368–1644 CE) were first time analyzed by micro-Raman, Fourier-transform Infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope with energy-dispersive X-ray microanalysis (SEM-EDX), thermogravimetry and differential scanning calorimetry (TG-DSC) to reach a better understanding of the composition of the materials and the techniques adopted.All the pigments were identified, including hematite, cinnabar, malachite, yellow ochre, calcite and carbon black. The preparatory layer was found to be prepared by fine lime mortar with cotton fiber inside. The crystalline depositions on the mural painting were identified as calcite and dolomite originated from the lime-based preparatory layer. The support was found to be constructed with sticky rice lime mortar with several kinds of additives. The original lime stone was demonstrated to be magnesium-rich and the carbonization results were also discussed.These results revealed significant information on the materials and techniques used to build mural painting tomb in Ming Dynasty. This will benefit the further restoration and conservation works and also provide a methodology solution for the scientific analysis of ancient tomb mural paintings.

Lower Ludfordian (Upper Silurian) slope deposits in the Lyagadin section (Ilych River, the Northern Urals)

Research subject. Upper Silurian (Lower Ludfordian) slope deposits of the Lyagadin section (Ilych River, Northern Urals).Materials and methods.The composition and structure of 40 rock samples collected across the section during fieldworks in 2019 were studied. Thin sections were examined under a polarising microscope. Eight samples were investigated by silicate analysis, and clay minerals from 2 samples were determined by X-ray diffraction analysis of oriented samples.Results. The Lyagadin section with a visible thickness of 70 m is represented by an uneven alteration of clayey-siliceouscalcareous schists, micro-grained limestones with burrows, micro-fine-grained layered limestones, fine lime sandstones, coarse- and medium-grained lime sandstones, lime conglogravelites and lime conglobreccias. Clayey-siliceous-calcareous schists and micro-grained limestones with burrows characterise the background periplatform clayey-carbonate deposits. The part of micro-fine-grained layered limestones (their horizontally layered varieties) are bottom current sediments. Gravity flow deposits are represented by clastic rock assemblage. The most characteristic of them is the assemblage composed of lime conglogravelites with an erosional bottom, which pass into gradational-layered lime sandstones, first coarse- and medium-grained, and further the into their fine-grained varieties. They are covered, in turn, with micro- fine-grained limestones with cross or convolute stratifications. That association is interpreted as calciturbidites. Calcidebrites are characterised by lime conglobreccias. The deposits of grainy flows (?) are represented by the layers of lime sandstones not revealing the characteristic features of the Bouma sequence.Conclusion. The reconstructed background sedimentation on the continental slope during Early Ludfordian was characterised by the accumulation of hemi-pelagic clay deposits together with a certain amount of microscopic quartz, orthoclase and organic matter. Periodically appearing thin layers of micro-grained limestones with burrows correspond to the periods of increased supply of carbonate material, which could be attributed to “marine snow”. The irregular nature of the distribution of gravity flow deposits in the Lyagadin section suggests that the studied slope deposits are, most likely, the formation of the outer apron of slope bottom, rather than calciclastic fans.

PROPERTIES OF CONCRETE CONTAINING CRUSHED LIMESTONE AS TOTAL REPLACEMENT OF NATURAL SAND AND RECYCLED ENGINE OIL

The rapid growth in the construction industry at the global level has made concrete the most widely used construction material throughout the world. Accordingly, the consumption of natural sand which is one the main raw material constituent of concrete is continuously growing. The demand for river sand is highly increasing due to its scarcity in the market. Manufactured sand produced by crushed rock is being considered as an appropriate alternative to replace river sand in concrete. In recent years, there is a growing interest in the use of crushed sand obtained from limestone quarries in some countries where river sand is not widely available”. The objective of this study is to investigate the effect of total replacement of the natural sand by fine aggregates obtained from crushed limestone. However, it needs more research on the crushed stone fine aggregates to reveal its engineering properties prior to utilization in concrete. Another objective of this study is to study the effect of using the waste engine oil as partial replacement of water reducing admixture. The use of waste engine oil in concrete is beneficial for the environment. It is to be noted that some countries are recycling this used oil but others are throwing it in the sea and harming the marine life. In this paper, different combinations and grading of fine lime stone and coarse aggregates were tried in order to attain the optimal proportion that provide an acceptable concrete performance in terms of workability and compressive strength. Also, different percentages of admixture replacement ranging from zero to one hundred percent of the used engine oil were tried in the selected optimal mixture proportion. The final selected proportion using engine oil and crushed limestone could be considered as an economical solution and friendly environmental concrete product.

Journey from ceramic waste to highly efficient toxic dye adsorption from aqueous solutions via one-pot synthesis of CaSO4 rod-shape with silica

Fine calcium oxide (CaO) which is the main component in the fine lime and considered as a waste byproduct from the steel manufacturing industry is converted into a potential composite to be used as an adsorbent. A facile and simple impregnation between CaO and silica in the presence of H2SO4 is utilized to achieve a one-step synthesis of a highly efficient CaO-based rod-shape composite with silica (CRCS). The suitability of using this composite in hazardous crystal violet (CV) cationic dye removal from aqueous solution was evaluated in series batch experiments. The synthesized composite was characterized using various techniques including XRD, SEM, TEM, EDX, FT-IR, and Raman to determine the adsorbent physicochemical properties. Influences of various operating parameters such as contact time, initial dye concentration, adsorbent dosage, agitation speed, initial pH, and reaction temperature were examined. The results of the experimental data well fitted Langmuir and the pseudo-first-order kinetic model. Based on the thermodynamic parameters, the sorption of CV onto CRCS is a spontaneous and endothermic process. The prepared CRCS also exhibited easily regeneration and recycling at least for ten adsorption–desorption runs. This study offers new insights into promising waste management technology that is efficiently applied to treat dye-contaminated water.

Execution technique and pigment characteristics of decorative wall from 17th CE Chatta Chowk, Red Fort Complex, New Delhi

The decorative wall painting from 17 th CE Chatta Chowk was investigated to study the composition and characteristics of the pigment used in the decorative arts. The pigments were examined by thin cross-sections, High-Resolution X-ray diffraction (HR-XRD) analysis, Fourier-transform infrared spectroscopy (FTIR) and, portable Raman spectrometry. Besides, gas chromatograph-mass spectrometry (GC-MS) was used for identifying pigment binders. Analysis results showed the stratigraphy of the paint layer applied over fine lime plaster in a well-controlled manner mixed with binders according to the secco technique. The identified pigments for red paint layers were attributed to the mixture of hematite (Fe 2 O 3 ), cinnabar (HgS) and cadmium sulfide (CdS). The utilization of admixture of mercury, iron and cadmium compounds has served as a clear evidence in order specific tones on the painted surfaces. The green paint layer was attributed to green earth (celadonite) through vibrational features, differentiating from glauconite spectra. The GC-MS analysis of the pigment showed the use of fats, waxes and drying oils as binders.

Optimizing the use of quicklime (CaO) for sea urchin management — A lab and field study

Mass blooms of sea urchins sometimes cause kelp forest collapses that can last for decades. Quicklime has historically been used to reverse those conditions, but the efficacy of liming has varied along latitudinal and temperature gradients for reasons that are not fully understood.To evaluate the feasibility and ecological impacts of liming in a high latitude area in Northern Norway (70°N), we conducted a field pilot study in 2008–2011, a follow-up lab study in 2017, and a further field study in 2018–2019, with the latter evaluating and implementing the previous results in a site high in refuges. It was found that liming can reduce sea urchin densities sufficiently for macroalgal revegetation to occur, and that the mobile fauna species richness and abundance increased in the re-vegetated in comparison to the barren control fields. Also, the remaining sea urchins in the treated fields increased their roe content to commercial levels after 2 years.The lab experiments in 2017 indicated that the liming method is season/temperature-independent, as mortality remained at the same level irrespective of whether treatment started in the spring, when the sea temperatures were 2 °C, or in autumn when the temperatures were closer to 10 °C. The most important factor in treatment efficacy in the lab was particle size. With similar doses, the particles in the smallest size range (0–0.5 mm) caused 100% mortality, while the 0.5–2 mm and 2–4 mm fractions caused only 13% and 2% mortality respectively.In 2018–2019 we tested the fine CaO fraction (0.1–0.6 mm) and the medium fraction (0.5–2 mm) in a field experiment in areas characterized by high levels of refuges. Within 11 days, the sea urchin densities in the three fields treated with the fine lime were reduced to levels that theoretically should allow revegetation, but only in one of those fields was that potential partly realized after 1 year. The lack of effect in the two other fields was probably due to urchins protected by the substrate during treatment reappearing in sufficient numbers to prevent macroalgal regrowth, demonstrating that CaO treatment can be less effective on substrates where part of the sea urchin population hides among stones.Of the three variables held up as potential explanations for the different effects of CaO treatment in previous studies, we conclude based on our experiments that the presence of refuges and particle size were probably more important than temperature. Further improvements for larger scale treatments are discussed.

Influence of binder characteristics on the setting and hardening of hemp lightweight concrete

Hemp concrete is an alternative building material used for insulation in low energy constructions. Experiments conducted with pure cement have generally led to poor binding properties, hence, commercial binders are often composed of a mix of hydraulic binder with lime. However, empirical observations in laboratories or onsite indicate that setting problems still may occur. This paper attempts to identify the phenomena that can explain the properties of mixed binders. With regard to hydration and mechanical performances, the results show that the addition of lime, especially fine lime, can reduce detrimental effects of hemp, but does not fully suppress them.

The effect of liming on antibacterial and hormone levels in wastewater biosolids

This study analyzes the effect of liming on levels of triclocarban (TCC), triclosan (TCS), estrone (E1), and progesterone (P), two antimicrobial agents and two natural hormones, respectively. Factors studied include lime particle size, mixing time, and overall lime contact time. The study results suggest that coarse lime may be more active than fine lime due to less interaction with surrounding air. Both TCS and TCC concentrations were lower in coarse limed samples versus unlimed samples and the decrease was a function of time. A similar, but statistically insignificant trend in TCC and TCS levels was observed in fine lime samples with respect to unlimed samples. Liming was also found to decrease apparent E1 levels, with more notable decreases in samples amended with coarse lime. P-levels significantly increased after 1-day of contact time, stabilizing over the next 14 days of the study period. This increase and stabilization of P-levels was attributed to the pH and moisture-driven conversion of more chemically complex steroids into P.

Activation of Slag Cement by Hydrated Lime

In this experimental study, the setting agent Ca(OH)2 used for activation of slag cement is used in the proportions of 0%, 2%, 4%, 6%, 8% and 10% by substitution method by mass of slag cement. The results indicated that the mineral activator has a significant effect on the flexural and compressive strengths. The optimum percentage of the mineral activator (hydrated lime) ranges between 2 to 4%. The activation of the slag cement by fine lime (calcium hydroxide) is a simple and economic method especially for cement containing not very reactive slag or low reactivity due to its low CaO/SiO2.

Desarrollo de hormigones con aglomerante cal-puzolana fina como material cementicio suplementario

La alta resistencia y durabilidad alcanzada en los hormigones de alta y ultra alta resistencia esta asociada a la obtencion de una matriz muy densa, definida a partir del uso de altos volumenes de adiciones minerales muy finas, tales como las cenizas volantes, microsilice, metacaolin y polvos finos de cuarzo. El trabajo muestra un estudio sobre el uso del aglomerante cal- puzolana (ACP) de alta finura, como adicion mineral activa en el hormigon. Las particulas muy finas de la cal, de tamanos entre las 0.1-10 m pueden llenar los vacios entre los granos de cemento, mientras las particulas mas grandes de la puzolana, entre 10-100 m, pueden llenar los vacios entre los granos mas finos del agregado, resultando en una matriz mas densa. La adicion de hidroxido de calcio (HC) durante el mezclado del hormigon, tambien incrementa la concentracion de iones Ca +2 y OH - , lo cual resulta en una mejor y mas rapida hidratacion del Cemento Portland Ordinario (CPO) y de la reaccion puzolanica. El uso de la ACP como adicion mineral activa en hormigones de alta resistencia (HAR), podria contribuir a disminuir los costos del producto sin afectar su resistencia mecanica y durabilidad usando menos cemento, con lo cual se estaria mejorando el perfil ecologico de este material. Resultados iniciales son mostrados en este trabajo, requiriendose de ensayos adicionales para establecer los beneficios del uso de la ACP en los HAR. Un ejemplo de aplicacion de este trabajo en hormigones son tambien presentados. Rev. ing. constr. [online]. 2008, vol.23, n.3, pp. 171-178. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732008000300005

Characteristics for the Hydration Reaction of Limestone Washing Process Sludge from Steel Works

In order to understand the fundamental features of hydration reaction of sludge generated from a limestone washing process at a steel works and to improve its utilization as a secondary resource, the physicochemical properties of the sludge were examined and its hydration characteristics were investigated under several different conditions. The sludge was mainly composed of CaCO3 and its thermal behavior was observed to be affected by its composition. Compared to the conventional methods for hydrating limestone, using an ultrasonic vibration reactor produced more impalpable slacked lime powder with an even grain size because of the uniform reaction to the entire pulp without a violent reaction. Adequate pulp density for the production of fine slaked lime in an ultrasonic vibration reactor was observed to be 10 wt% or less. Hydration of the sludge formed by the limestone washing process was better and produced more homogeneous fine slacked lime powder than that of natural limestone. Slaked lime powder formed from the limestone washing-based sludge was very minute and the hydration reaction was completed within 10 minutes. In addition, the degree of hydration of the limestone washing-based sludge was found to be higher than that of natural limestone.

The effect of two lime sources on short-term changes in soil pH under Marlborough hill country pasture

The effect of fine slurried lime applied at 200 kg/ha on soil pH at two depths was compared with 400 and 2500 kg/ha of local agricultural (ag) lime in the presence and absence of sulphur (S) superphosphate 20, in Marlborough hill country for one year. In the absence of fertiliser all lime treatments significantly raised soil pH in the top 25 mm for the 355 days after application. Initial responses declined from day 14 or 35 to day 138 before increasing at day 355. Fine lime did not significantly alter pH in the 25-75 mm zone until day 355. The low rate of ag lime significantly raised pH in the 25-75 mm zone for the whole year. The high rate of ag lime significantly increased pH in the top 25 mm over the other lime treatments for the 355 days and over the fine lime treatment in the 25-75 mm zone from day 35. In the presence of fertiliser in the top 25 mm, fine lime significantly increased pH at day 14 only, and low ag lime at day 355 only. The high rate of ag lime significantly increased pH over the control from day 14 and over the other lime rates from day 35. In the 25-75 mm zone the high rate of ag lime significantly increased pH over the control and the low ag lime rate from day 71 but was significantly better than fine lime from day 35. It is likely that rain immediately after application and higher than average annual rainfall hastened the release of fine and intermediate particles of lime. However provided lime meets the accepted criteria for particle size distribution and maximum size it is the rate of application which dictates the magnitude of response. In Marlborough hill country it was 43% cheaper to aerially apply 400 kg/ha of ag lime compared to 200 kg/ha of fine lime with the added benefit of a greater residual effect beyond one year. Keywords: agricultural lime, fine lime, slurry, soil pH

High-frequency relative sea level variation cycles recorded in sedimentary discontinuities

Abstract In the Lodève region (“Caussenard High” southwestern margin of the South-East Basin), upper Hettangian to Lotharingian carbonate series shows more than twenty sedimentary discontinuities of various types. Some of these discontinuities are polyphase surfaces, which record high-frequency sea-level variation cycles. One of these discontinuities has been studied in detail, in order to understand its origin (processes, chronology of formation). Several stages of formation have been recognized. A transgressive erosion occurred first. Next, development of Skolithos and Diplocraterion burrows, associated with iron mineralizations, could be indicative of a condensation phase corresponding to the subsequent maximum-flooding period. The burrows sparitic fills may characterize the highstand period following the maximum-flooding period. Next, alteration and corrosion observed on the surface and in the burrows may indicate an emersion related to a regressive phase and the subsequent lowstand period. Finally, micro mud-mounds (formed by pelecypods and corals trapping fine lime sediment) may indicate a new condensation phase, associated with the transgression and the following maximum-flooding period. Thus, this discontinuity records one and a half relative sea level variation cycle. Counting sequences observed in the deposits and in the discontinuities leads to an estimate of 100,000 years duration for these cycles. That could correspond to the eccentricity variation cycles. Moreover, the local synsedimentary tectonics may have influenced the formation of this type of discontinuity, by forming shallow restricted environments favourable to their development. Recognition and understanding of these particular discontinuities are essential because they may be laterally correlated with other surfaces in continental settings (paleokarst) or with classical sequences in marine environments.

Movimentação de partículas de calcário no perfil de um Cambissolo em plantio direto

A aplicação superficial de calcário tem-se mostrado eficiente na correção da acidez do solo no sistema plantio direto. Ao contrário do esperado, os efeitos da aplicação de calcário têm ocorrido em profundidade e em períodos de tempo relativamente curtos, apesar da sua baixa solubilidade no solo. Os objetivos deste trabalho foram: (a) detectar a presença dos minerais calcita e dolomita do calcário no solo; (b) verificar as alterações químicas relacionadas com a acidez no perfil do solo, decorrentes da aplicação de calcário na superfície, e (c) verificar a movimentação de partículas de calcário e a sua participação na correção da acidez do solo no sistema plantio direto. Foi realizado um experimento em casa de vegetação, utilizando colunas de PVC com amostras indeformadas de um Cambissolo Húmico alumínico léptico argiloso, manejado há cinco anos em sistema plantio direto. A dose de calcário comercial (PRNT 76 %) aplicada no topo da coluna correspondeu a 12 Mg ha-1. Aos sete dias da aplicação do calcário, já foi possível verificar o transporte de partículas finas (< 0,105 mm) do calcário aplicado na superfície do solo até à profundidade de 20 cm, visto que foram detectados os minerais calcita e dolomita nesta profundidade. Os efeitos nos atributos químicos do solo, decorrentes da aplicação de calcário na superfície, ocorreram em todo o perfil, sendo mais expressivos até 10 cm e aos 20 cm de profundidade, onde houve acúmulo de calcário. O transporte de calcário através da água da chuva pode ser um mecanismo importante na correção da acidez do solo em profundidade no sistema plantio direto.

Modeling flue gas desulfurization by spray-dry absorption

Abstract A detailed model for flue gas desulfurization by spray-dry absorption with a lime slurry is presented. The model combines a steady state one-dimensional spray-dryer model with a single-drop model for SO2 absorption with instantaneous irreversible reaction in a rigid droplet containing uniformly dispersed fine lime particles. The fate of the droplets is followed from atomization until formation of a porous coherent shell around the drying droplets. The model results were validated against available experimental spray-dry FGD results, showing excellent agreement at low to medium Ca/S feed ratios. The model was then used to study the relevance of the different resistances to SO2 absorption and to predict the influence of the main operating variables on the spray-dryer desulfurization performance. Analysis of variables profiles along the spray-dry column showed that the initial droplet velocity has no influence on model results and that the initial droplets decelerating phase always accounts for negligible SO2 capture. Results further showed that the controlling resistance to SO2 absorption shifts from a liquid-phase one near the atomizer to a gas-phase one at the column exit. The operating variables that exert the largest influence on the overall desulfurization efficiency are the Ca/S molar feed ratio, the mean initial droplet size and the mean lime particle size. In particular, careful control of the last two variables is critical in order to obtain a good spray-dryer performance.

無機塩による微粒子生石灰の改質を利用した粉粒流動層での高効率乾式脱硫

無機塩による微粒子生石灰の改質を利用した粉粒流動層での高効率乾式脱硫

98/02428 Flue gas desulfurization of lignite-fired power stations with limestone or fine lime : Breuer, H. et al. ZKG Int., 1997, 50, (11), 646–648, 649–650, 652–654, 656. (In English/German)

98/02428 Flue gas desulfurization of lignite-fired power stations with limestone or fine lime : Breuer, H. et al. ZKG Int., 1997, 50, (11), 646–648, 649–650, 652–654, 656. (In English/German)

A model for gas—solid stratified flow in horizontal dense-phase pneumatic conveying

On the basis of understanding the interaction mechanism between suspension and sliding bed, a physical model has been developed for gas—solid stratified flow with high solids/gas mass flowrate ratio (so-called solids loading) in horizontal pneumatic conveying. It was found that the predicted pressure drop from the developed model coincides within ±30% with the experimental data for conveying medium size sand and fine lime in an 8 m long pipe with a diameter of 20 mm under a wide range of solids loading from 30 to 200. Also, predictions for phase diagram, flow configuration and velocity of sliding bed seem to be more reasonable from the present model than previous models.

Particle size determines the efficiency of calcitic limestone in amending acidic soil

There is a commonly held view that limestone particles <0.25 mm are fully effective in amending acidic soils. However, this is not consistent with some available data. We assessed the importance of particle size in a field experiment using six particle size segregations covering a range of mean diameters from 3 mm to 0.005 mm. These products were applied at rates of 2.5, 5 and 10 t ha-1. Lime was incorporated in April 1986 and soil samples were collected 6, 12, 24 and 36 months later. The experiment was cropped to wheat in 1986, 1987 and 1989. Effectiveness was evaluated as the capacity of the particle size segregation to increase soil pH, exchangeable calcium (Caex,) or grain yield of wheat. No minimum particle size for maximum effectiveness was identified. Throughout the range of particle sizes evaluated, progressively finer particles produced larger increases in pH and Caex. Wheat yield was related to soil pH. Changes in soil pH and Caex between 6 months and 3 years after lime application were small compared to the changes in the first 6 months. Fine lime products should be preferred in practice, subject to cost considerations and handling difficulties.

Sticking prevention during fine-ore metallization in two-stage smelting-reduction processes

Parameters known to have an influence on the sticking tendency of fine iron ores during reduction are discussed in view of their practicability in smelting-reduction processes. The low sulfur concept, the admixture of inert materials and the coating of the ore particles with carbon are looked at more closely. Sticking tests in a laboratory fluidized bed with a number of iron ores were carried out to investigate the effectiveness of inert additives and of carbon deposition. While the admixture of fine coke and lime could not prevent sticking during metallization, carbon deposition from CO proved to be effective even for ores with strong sticking tendencies