Calcium Limestone Research Articles

The Properties of White Mineral Trioxide Aggregate (WMTA) Made of Rice Husk Ash Silica and Limestone Calcium Carbonate and the Effect of Silica Particles Addition

White Mineral Trioxide Aggregate (WMTA) using a combination of precursors consisting entirely of SiO2, CaCO3, Al2O3, and Bi2O3 which are widely used as cement for tooth restoration has been prepared. SiO2 was extracted from rice husk ash containing about 85-95% of silica found in rice husk ash from complete combustion. On the other hand, rice husks, in general, are still regarded as agricultural waste resulting from the rice milling process. In the rice milling process, around 20-30% of rice is obtained, and around 14-20% of ash is produced from burning rice husks. CaCO3 can be synthesized from limestone and it contains about 95% calcium carbonate. In this research, the researcher made WMTA from rice husk silica and CaCO3 from limestone. This research was carried out in several stages of silica extraction from rice husk ash using the high-purity sol-gel method, then the synthesis of calcium carbonate with the carbonation method obtained precipitated calcium carbonate (PCC). Preparation of WMTA by reacting silica sonicated + PCC + Al2O3 accompanied by stirring and heating 85 °C for 24 hours for homogenization, gelation, and maturation processes will be obtained by MTA’s gel. The MTA gel dried and calcined 1000 °C for 3 hours to obtain a white powder, the final product was added Bi2O3 of 18% produced high-quality WMTA. The results of making WMTA and modification silica of rice husk ash and PCC from limestone were characterized using XRD, FTIR showed characters that had similarities with WMTA ProRoot and had better diameter tensile strength test capabilities.

Study on the Factors Affecting the Determination of Calcium in Limestone for Chemical Industry by AAS

The calcium content in limestone for chemical industry was determined by atomic absorption spectrometry. The effects of soaking time, soaking reagent and soaking temperature on the determination of calcium content in limestone for chemical industry were discussed by the method of controlling variables, and the optimum conditions for the determination of calcium content in limestone for chemical industry were analyzed. This method has the advantages of easy operation, low interference, high accuracy and sensitivity, and is widely used. The experimental results show that the optimum conditions for the determination of calcium content in limestone for chemical industry are as follows: soaking reagent is 0.6mol/L hydrochloric acid, soaking time is 0.5h, soaking temperature is 70～80 ℃.

True ileal digestibility of calcium in limestone and dicalcium phosphate are additive in diets of broiler chickens

The experiment was conducted to test if the true ileal digestibility (TID) of Ca in limestone and dicalcium phosphate (DCP) are additive in mixed diets for Ross 708 broiler chickens from day 22 to 27 post-hatching. The birds were fed a standard broiler starter diet from day 1 to 22 post-hatching. A total of 504 birds were grouped by BW into 8 blocks of 9 cages with 7 birds per cage and assigned to 9 dietary treatments in a 3 × 3 factorial arrangement of 3 Ca sources including limestone, DCP, and their mixture at a ratio of 1:1, and 3 dietary Ca concentrations at 3.3, 4.3, and 5.3g/kg. Potassium phosphate was added to adjust the dietary P concentration and maintain a 1.1:1 total Ca:non-phytate P ratio. The results showed that the Ca intake, ileal Ca digested, and Ca retained linearly increased as the Ca concentration increased (P < 0.001). No Ca concentration effect was observed on apparent ileal digestibility of Ca (P = 0.13). By regressing digested Ca per bird against Ca intake per bird, the TID of Ca was determined at 63.7, 67.1, and 67.8% for limestone, DCP, and their mixture, respectively. The expected TID for Ca in limestone and DCP mixture was predicted to be 65.1% based upon the Ca contribution coefficient calculated to be 0.59 for limestone and 0.41 for DCP. The predicted TID of Ca (65.1%) in the mixture was not different (P = 0.63) from the determined TID of Ca (67.8%). In conclusion, the TID of Ca in limestone and DCP are additive in semi-purified diets for chickens.

Study of hydration process of ternesite clinker

Currently ternesite, Ca5(SiO4)2SO4, is used in the cement production, is one of two key phases of calcium sulfoaluminate cement. Some investigators claim that this phase is nearly inert or very low reactive and it hydrates only after later age of hydration. In order to improve knowledge in this field, process of hydration of neat ternesite clinker under specific conditions of exposure was observed in this study. Ternesite was prepared by firing of raw meal consisting of high calcium limestone, microsilica and calcium sulfate hydrate. The resulting ternesite clinker was subsequently hydrated in four storage environments. Kinetics of hydration process was monitored in water and in environment of saturated carbonic acid, at two different temperatures of 5 and 40 °C. Mineralogical composition of hydrated samples was analyzed by X-Ray diffraction analysis (XRD) and by differential thermal analysis (DTA) in particular ages of hydration. Based on the results, it can be claimed that rate of decomposition of ternesite was related to conditions of storage. The rate of decomposition was significantly accelerated by the environment of carbonic acid and also by the elevated temperature. Presence of calcium carbonates in mineralogical forms of calcite, vaterite and aragonite, coupled with gypsum and thaumasite was identified.

True is more additive than apparent total tract digestibility of calcium in limestone and dicalcium phosphate for twenty-kilogram pigs fed semipurified diets.

Two experiments were conducted to determine the Ca digestibility of limestone and dicalcium phosphate (DCP) and if values for Ca digestibility are additive in mixed diets for pigs. In Exp. 1, 48 barrows with an average initial BW of 19.2 ± 1.1 kg were assigned to 1 of 6 dietary treatments in a 2 × 3 factorial arrangement of 2 Ca sources, including limestone or DCP, and 3 dietary Ca concentrations of 0.54, 0.74, or 0.94%. Diets were fed for a 5-d adjustment period followed by a total collection period of 5 d with chromic oxide and ferric oxide as markers to determine the initiation and termination of fecal collection, respectively. Results indicated that the increased dietary Ca concentration linearly increased ( < 0.01) Ca intake, digested Ca, and retained Ca but did not affect the apparent total tract digestibility (ATTD) of Ca or Ca retention of intake (%). The ATTD of P and P retention of intake were linearly increased ( < 0.05) as dietary Ca and P increased. In Exp. 2, 72 barrows with an average initial BW of 20.8 ± 1.3 kg were assigned to 1 of 9 dietary treatments in a 3 × 3 factorial arrangement of 3 Ca sources, including limestone, DCP, or the mixture of the 2 at a ratio of 1:1, and dietary Ca concentrations of 0.40, 0.50, or 0.60%. Feeding and sample collection procedures were as in Exp. 1. The results also showed that increased Ca concentration linearly increased ( < 0.001) Ca intake, fecal Ca output, and Ca absorbed but did not affect the ATTD of Ca within each Ca source. The average ATTD were 66.46, 70.34, and 69.32% for the limestone, DCP, and mixed diets, respectively. By regressing daily digested Ca against daily Ca intake, the true total tract digestibility (TTTD) of Ca was determined to be 70.06, 76.42, and 73.72% for the limestone, DCP, and mixed diets, respectively. The predicted TTTD for Ca in the mixed diets of limestone and DCP was calculated to be 72.67% based on the Ca contribution coefficient of 0.59 for limestone and 0.41 for DCP. The predicted Ca TTTD (72.67%) in the mixed diets was not different from the Ca TTTD (73.72%) determined using the regression method. It is concluded that although the ATTD of limestone and DCP were not affected by the Ca concentration in the diet, TTTD is recommended for evaluation of Ca digestibility because of its additivity in a mixed diet.

182 True total-tract digestibility of calcium in limestone and dicalcium phosphate for twenty-kilogram pigs are additive in a semi-purified diet

182 True total-tract digestibility of calcium in limestone and dicalcium phosphate for twenty-kilogram pigs are additive in a semi-purified diet

Apparent ileal digestibility of calcium in limestone for broiler chickens

The objective of the study that is presented herein was to determine the apparent ileal calcium (Ca) digestibility of limestone for broiler chickens as influenced by limestone source and dietary phosphorus (P) concentration. Limestone from three commercial sources (coded as LM-1, LM-2 and LM-3) were obtained, ground to pass through a 0.2mm sieve and analysed for mineral composition and in vitro solubility. Analysed Ca concentration and in vitro solubility coefficient of LM-1, LM-2 and LM-3 were 410, 390 and 420g/kg, and 0.28, 0.29 and 0.27, respectively. Two experimental diets, containing 9g/kg Ca, were developed from each limestone source with 0 and 4.5g/kg dietary P. Titanium dioxide was incorporated as an indigestible marker. Each experimental diet was then randomly allotted to six replicate cages (eight birds per cage) and fed from day 21 to 24 post-hatch. Apparent ileal digestibility of Ca was calculated using the indicator method. Apparent ileal Ca digestibility coefficients of LM-1, LM-2 and LM-3 were determined to be 0.58, 0.61 and 0.54, respectively. Calcium digestibility of LM-3 was lower (P<0.05) than LM-2 but similar (P>0.05) to LM-1. There was no difference (P>0.05) between the Ca digestibility of LM-1 and LM-2. Increasing the dietary P concentration from 0 to 4.5g/kg in assay diets increased (P<0.05) the average Ca digestibility from 0.56 to 0.60.

Consumo e desempenho de novilhos alimentados com borra de soja em confinamento

This study was designed to evaluate the feasibility of using soybean dreg in finishing of confined steers, with age and initial body weight of 20 months and 328.3 kg, respectively. Each treatment consisted of six experimental animals, which were fed with forage: concentrate ratio, 40:60 (dry matter basis), being bulky corn silage and concentrate based of bark, chaff and soybean dreg, corn, sodium chloride and calcium limestone. The steers were distributed in the treatments: 00, 30, 60, 90 and 120 g of soybean dreg per kg of dry matter in the diet, which contained 29.0, 47.3, 66.7, 86.8 and 106.8 g of ether extract, respectively. The dry matter intake was similar (P> 0.05) among the studied treatments with an average of 9.71 kg day-1. Similarly, no differences were observed (P> 0.05) in crude protein intake with anaverage of 1.36 kg day-1. However, there were differences in the consumption of ether extract and neutral and acid detergent fibre, which decreased linearly with the increase in the inclusion of dreg in the diet (CEE=0,305+0,0061SD; CFDN=5.71–0,011SD; CFDA=3.89–0.008SD kg day-1, respectively). The performance of steers was similar (P>0.05) between treatments, being the average daily gain of 1.542 kg, the fed conversion of 6.35 kg DM kg-1 weight gain and slaughter weight of 457.95 kg. The use of soybean dreg until the limit of 120 g kg-1 in the diet of confined cattle is feasible.

Recovery of sawdust resulting from marble processing plants for future uses in high value-added products

The disposal of microfine marble sawdust contained in marble slurry waste, currently represents an additional economic burden for dimension stones companies. This is because the sawdust is considered less important in comparison with the crushed calcareous aggregate produced in stone processing plants. In addition, the sludge is mistakenly viewed as waste that has to be disposed of in landfill. State of the art in recovery and utilisation of calcareous sawdust is mainly aimed in uses as substitute for more expensive ingredient in the building sector. Moreover limestone dust, recovered from marble sawing and processing slurry, has not yet found real economically feasible industrial usage. Due to the high market value of micronised CaCO3, we study the use of limestone sawdust as functional filler in industrial products having higher added value, such as paper, rubber, paints, pharmaceuticals. Standard requirements of CaCO3 for this kind of products are very tight, especially those relating to purity level, particle size distribution and brightness. The high Calcium limestone deposit and the factories in Orosei Marble producing area (Sardinia, Italy) allow the production of high quality microfine dust. To evaluate the properties of the sawdust, several analysis were carried out to compare the results with the standard requirements of CaCO3 for paper, rubber and tyre production. The assessment concerns five different factories and it highlights the possible usage of the sawdust produced in Orosei by carrying out simple and inexpensive changes in both stone-working process and wastewater treatment. Finally, a commentary on environmental laws pertaining to the recycle of this kind of waste is also made in this paper.

Reduction of fuel side costs due to biomass co-combustion

The feasibility and influence of co-combustion of woody biomass on the fuel side costs is discussed for three hard coal power plants located in Berlin, Germany. Fuel side costs are defined as the costs resulting from flue gas cleaning and by-products. To have reliable data, co-firing tests were conducted in two power plants (i.e. slag tap furnace and circulating fluidising bed combustion). The amount of wood which was co-fired varied at levels below 11% of the fuel heat input. Wood chips originating from landscape management were used. The analyses show that co-combustion of woody biomass can lower the fuel side costs and that the co-combustion at a level below 10% of the thermal capacity is technically feasible without major problems. Furthermore, a flexible spreadsheet tool was developed for the calculation of fuel side costs and suggestions for operational improvements were made. For example, the adaptation of the Ca/S ratio (mass ratio of calcium in limestone to sulphur in the fuel) in one plant could reduce the fuel side costs up to 135k€yr−1(0.09€MWh−1).

Milk quality of Jersey cows kept on winter pasture supplemented or not with concentrate

This study was carried out to evaluate the effect of the use of supplementation in pasture cultivated with Avena strigosa (black oats), Lolium multiflorum (ryegrass) and Vicia sativa L. (common vetch) on the composition and somatic cells count (SCC) of Jersey cow milk. Eight cows of the Jersey breed were separated by milk production, lactation period and live weight and were randomly blocked into two homogeneous groups (one with supplementation and other only on pasture), in a randomized complete design. Both groups were allowed to pasture for about 7 hours per day in a rotational grazing system in strips, with a one-day occupation period. The supplemented group was fed daily with 8 kg of supplement made of soy bean meal, soy shells, calcium limestone and mineral salt. The results showed significant differences between the two groups, because the percentage of total solids, protein and milk fat were higher in the supplemented cows. The lactose percentage was not influenced by the supplement intake. The somatic cell count, although there was a lower statistical difference for the group on pasture, showed small numerical oscillation between the groups and therefore should not be considered an effect of supplementation. The supplement supply to Jersey cows during lactation caused an increase in the total milk solid percentage, because it raised the fat and protein concentration.

Effect of Limestone Particle Size Upon Calcium Bioavailability to Poults

In order to determine the availability of calcium in limestone processed by a new method, nine hundred day-old male poults were fed diets with varying calcium sources, levels and finenesses (mesh) for twenty-one days. Growth rate and feed efficiency were the criteria used to evaluate the availability of calcium among treatments.Reductions in the percent calcium in the diet produced significant decreases in gain with the coarser grinds of limestone. The birds showing greatest gain were on the 103 mesh (the particles were no larger than 1/1000th of an inch in diameter) at 1.30% calcium level. At the 0.80% and 0.60% calcium levels the poults on the Colorado Lien diets exhibited reduced growth compared to the poults receiving smaller particles; indicating that a reduction in particle size increased calcium availability at these lower dietary calcium levels.It was a general trend with the turkeys on the “mesh” diets that as the dietary calcium level dropped, the feed efficiency also dropped; however, this trend was not followed by the Colorado Lien poults and the CaCO3 birds. The most efficient poults in this experiment were the ones on the 102 mesh diet and the 102 mesh diet at the 1.30% calcium level. The least efficient were on the 102 mesh diet at 0.60% calcium level.In summary it can be stated that the finer grinds of limestone: 1) increased the availability of calcium to the poult, 2) increased the efficiency of the bird at low dietary calcium levels, and 3) produced better weight gains at low diet calcium levels. The coarser grinds increased weight gains and efficiencies at the highest calcium level. It was concluded that fine particle size in a limestone product increased dietary calcium availability to poults and probably reduced the amount of limestone needed in a poult’s diet.

Electric Utility Plant Flue-Gas Desulfurization—A Potential New Market for Lime, Limestone, and Other Carbonate Materials

Abstract Among many processes under consideration for flue-gas desulfurization, wet scrubbers that use lime, limestone, or other carbonate materials as the reactant appear to be the most advanced. The quantity of lime, limestone, or other carbonate material required for flue-gas desulfurization for a particular plant would depend on sulfur content and the amount of fuel burned, the type of scrubber system used, and, most important, the level of sulfur oxide emissions permitted for the area. Using 1972 electric utilities fuel consumption data, it is estimated that the widespread installation of wet scrubber systems on steam electric power plants would create a large market for lime, limestone, and other carbonate materials. Over 75 percent of this potential demand would be concentrated in the following eight states: Ohio (15.8%), Indiana (14.0%), Kentucky (9.5%), Pennsylvania (9.4%), Illinois (8.6%), Michigan (8.5%), Alabama (6.8%), and Tennessee (4.6%). The impact of wet scrubber installations on the lime and limestone industry would be substantial. It is estimated that even at 1972 fuel consumption levels the installation of limestone scrubbers could have required up to 28.0 million tons of high calcium limestone or other carbonate materials—equivalent to about 15% of the total amount of high-calcium limestone and other carbonate materials produced in the United States during that year. If, on the other hand, lime scrubbers had been installed, the potential demand would have amounted to at least 10.4 million tons of lime-51.3% more than the amount produced in the United States during 1972.

The immediate and long-term value of some magnesium fertilizers for sugar beet

SUMMARYNine 5-year field experiments between 1964 and 1971 tested the effect of kainit, kieserite, magnesium and calcium limestone, and farmyard manure on yield and magnesium uptake by sugar beet and on exchangeable soil magnesium. The experiments were in the main sugar beet growing areas on soils that contained little (12–24 ppm) exchangeable magnesium. The fertilizers were applied in the year before the first sugar-beet crop and fresh dressings of some were given to other plots each time sugar beet was grown. Kieserite increased sugar yield equally when applied in the sugarbeet seed bed or three years before the sugar beet. Magnesium limestone was effective only when the soil pH was less than 7·0. FYM greatly increased yield but the increase could not be explained entirely by the magnesium it supplied.On average, applying 100 kg/ha magnesium (as kieserite) to the seed bed increased the magnesium concentration in dried tops and roots by about 0·135 and 0·020% respectively and the total uptake by the crop in August by 9·0 kg/ha. The same treatment applied in the sugar-beet seed bed or 3 or 4 years previously increased exchangeable magnesium in the surface 25 cm of soil by 29·0, 7·6 and 1·8 ppm respectively. Thus much of the fertilizer given to the first sugar-beet crop was lost from the plough layer for the second sugar-beet crop but the yields indicated that some of it was available from depth.On alkaline soils, when exchangeable soil magnesium in the plough layer is 0–25, 26–50 or &gt; 51 ppm, an initial application of 100, 50 or 0 kg/ha respectively of water-soluble magnesium is needed, applied either in the previous autumn or to the sugarbeet seed bed. If the exchangeable soil magnesium before the following or subsequent sugar-beet crop is 0–15, 16–25 or &gt; 26 ppm, a further application of 100, 50 or 0 kg/ha respectively of magnesium should be given.

The Utilization by the Chick of Calcium from Different Sources

SEVERAL sources of calcium are used in poultry feeding. Experimental data indicate that the biological availability of calcium from most of these sources is essentially equal. Buckner et al. (1923) reported that limestone or oyster shell serve equally well as sources of calcium for laying hens. The calcium in limestone, gypsum, calcium gluconate, and dolomite were reported by Deobald et al. (1936) to be equally available although differences in solubility of the supplements were observed. Buckner et al. (1929) compared calcium lactate, chloride, sulphate and carbonate and concluded that the calcium carbonate was most effective for egg production as judged by egg shell The calcium in limestone, gypsum, calcium weight. Bethke et al. (1930) found no difference in the availability of calcium in the carbonate, sulfate, lactate, and phosphate salts or from limestone for bone formation in the growing chick on equal calcium intake. Dougherty and Gossman (1923) reported limestone…

The Temporary Injurious Effect of Excessive Liming of Acid Soils and its Relation to the Phospate Nutrition of Plants1

Greenhouse studies were conducted with the purpose of determining the cause of the injurious effects of overliming on plant growth. The results obtained may be briefly summarized as follows: 1. Nine out of 10 acid soils ranging in pH from 4.4 to poorer growth of alfalfa when brought to pH values near neutrality than when lower amounts of calcium carbonate were used, the average decreased yields when the pH values were slightly above 7.0 being 46%. With five of the nine soils the overliming injury to alfalfa disappeared after the first year. 2. Corn grown on an acid Dekalb loam which had been limed to pH values of approximately 6.5 and 7.5 showed marked injury and developed a light green to purplish color characteristic of phosphorus starvation. Additions of manganese sulfate, magnesium sulfate, ferrous sulfate, iron humate, or large amounts of muriate of potash did not correct this condition. The additions of large amounts of mono-calcium phosphate, mono-potassium phosphate, or silica gel, however, overcame the injury. Likewise the substitution of increasing amounts of magnesium carbonate for calcium carbonate, up to 75%, markedly improved growth and produced normal leaf color where the largest amount was added. 3. The materials that overcame liming injury materially increased the water-soluble phosphate in the soil solution and soil extract. 4. In a comparison of four different liming materials added in sufficient amounts to bring an acid Dekalb loam to pH 7.0, corn and rape made much better growth with dolomitic limestone or calcium silicate than with calcium limestone or calcium carbonate; the plants in the latter cases likewise showed marked symptoms of phosphate deficiency. The differences thus obtained were found to be explained by the larger concentrations of water-soluble phosphate where the dolomitic limestone and calcium silicate sources had been used. When the liming materials were added in amounts to bring the soil to pH 5.8, no liming injury was obtained and there was little difference in growth from the use of the various liming materials. 5. The corn plants grown on the soil limed to pH 7.0 had a higher ash content and a lower percentage of magnesium and phosphorus on the ash basis than plants grown at pH 5.8. Excluding the dolomitic limestone treatment some evidence was obtained of a relationship between the injury from excessive liming and the calcium-phosphorus ratio of plants. 6. It is concluded that the temporary overliming injury obtained in these experiments is due to a disturbed phosphate nutrition.