Showing papers on "Lime published in 1978"
TL;DR: In this article, the effect of lime on organic N mineralization was investigated in 40 acid surface soils of pH 4.0-5.6 with and without lime, and the amounts of organic N that were mineralized or nitrified were statistically compared with several soil acidity characteristics.
Abstract: Forty acid surface soils of pH 4.0–5.6 were incubated with and without lime, and the amounts of N that were mineralized or nitrified were statistically compared with several soil acidity characteristics. In addition, three field experiments were used to find the effect of liming on N mineralization. There was no relation between the amounts of mineral N released per unit of organic N in 120 days of incubation and soil pH, base saturation or soluble Fe, Al or Mn. Despite this, liming the soils to about pH 6.7 approximately doubled the amounts of N mineralized during incubation. In the field experiments, lime increased uptake of soil N by 15–42 kg/ha in the 1st yr but only 7–10 kg/ha in the 3rd yr. Thus these laboratory and field experiments indicate that soil acidity does not restrict mineralization of organic N and although liming increases mineralization of N, it is generally a temporary effect. Nitrification in the 40 incubated soils occurred much more rapidly in cultivated soils than in virgin soils. F...
149 citations
TL;DR: In this article, the influence of Ca(OH) 2, CaSO 4 ·2H 2 O and Na 2 SO 4 on the C 3 A hydration was examined in order to study the retardation mechanism caused by lime and/or gypsum additions.
133 citations
TL;DR: In this article, the properties of cement, lime and bitumen stabilized lateritic soils and made recommendations for field trials for road construction, the recommended percentages of cement are 3 percent for A1 and A2 soils; 5 percent for a4 soils and 7 percent for an A6 and A7 soil.
Abstract: Summary This paper is the final of a series concerned with work conducted at the Ahmadu Bello University on lateritic soils. It summarizes the properties of cement, lime and bitumen stabilized lateritic soils and makes recommendations for field trials. For road construction, the recommended percentages of cement are 3 percent for A1 and A2 soils; 5 percent for A4 soils and 7 percent for A6 and A7 soils. Only A2 soils are recommended for stabilization with lime as base materials and a minimum of 6 percent lime should be utilized for field trial. Bituminous stabilization should be used for the sub-base course only on lightly trafficked roads. The recommended soils are A1, A2 and A3; and 2 to 4 percent of bitumen is recommended for field trial in the first instance. Soil cement stabilization for low cost one storey buildings is advocated. 5 percent cement content is recommended in the first instance but this could be reduced depending on laboratory results. Reasons for the better success of cement stabilization with lateritic soils are discussed.
125 citations
91 citations
TL;DR: The valuable role of high-pH lime treatment in reducing the load of pathogenic microorganisms on subsequent units, including ultimate disinfection processes, is illustrated, which is important in the multiple safety barrier concept of wastewater reclamation processes.
Abstract: Lime flocculation/sedimentation in the first process unit of a 4,500-m3/day wastewater reclamation plant reduced numbers of microorganisms extensively when operated at pH 11.2. The efficiency was much less at lower pH values, and some bacteria even multiplied at pH 9.6. Data on reduction in the number of microorganisms in the lime treatment and subsequent units indicate that inactivation by hydroxide alkalinity plays an important role in the efficiency of lime treatment. Reductions in the numbers of enteric viruses were higher than those of coliphages, enterococci, and total plate and coliform bacteria, which indicate that lime treatment can be monitored by means of coliphage and conventional bacteriological tests. This paper illustrates the valuable role of high-pH lime treatment in reducing the load of pathogenic microorganisms on subsequent units, including ultimate disinfection processes, which is important in the multiple safety barrier concept of wastewater reclamation processes.
80 citations
TL;DR: In this paper, a brief review of the geology of the black cotton soils of northeastern Nigeria has been given, showing that the soils are predominantly kaolinite and montmorillonite, and that a mixture of both lime and cement is necessary for adequate stabilization of road bases for heavy wheel loads.
60 citations
TL;DR: In this paper, the mineralization of Carbon and Nitrogen in Forest Humus as Influenced by Additions of Phosphate and Lime is discussed. But the authors do not consider the effect of the addition of lime.
Abstract: (1978). Mineralization of Carbon and Nitrogen in Forest Humus as Influenced by Additions of Phosphate and Lime. Acta Agriculturae Scandinavica: Vol. 28, No. 3, pp. 221-230.
49 citations
TL;DR: In this paper, a mixture of lime, colloidal silica and quartz was treated hydrothermally in stirred suspensions at 180°C to prepare 11 A tobermorite with Ca/Si = 0.8.
46 citations
TL;DR: In this article, the ultrastructure and crystallography of the reaction products obtained by the in situ and in vacuo thermal decomposition of calcite in the transmission electron microscope (TEM) were reported.
Abstract: CALCIUM carbonate decomposes on heating to form calcium oxide—the quicklime or unslaked lime of industry. Because of its commercial significance any information concerning the nature of the CaO phase is important. I report here on the ultrastructure and crystallography of the reaction products obtained by the in situ and in vacuo thermal decomposition of calcite in the transmission electron microscope (TEM).
43 citations
TL;DR: The observation that plants infected by cassava mosaic disease grew no worse than symptomless plants, apparently free of the disease, clearly indicates the need for further investigations on the nutrient responses of cassava under field conditions.
35 citations
Patent•
23 Jun 1978
TL;DR: In this paper, the impregnation of porous lime particulates with iron oxide is used to improve lime utilization for sulfurous oxides adsorption in fluidized combustion of carbonaceous fuels.
Abstract: Lime utilization for sulfurous oxides adsorption in fluidized combustion of carbonaceous fuels is improved by impregnation of porous lime particulates with iron oxide. The impregnation is achieved by spraying an aqueous solution of mixed iron sulfate and sulfite on the limestone before transfer to the fluidized bed combustor, whereby the iron compounds react with the limestone substrate to form iron oxide at the limestone surface. The iron oxide present in the spent limestone is found to catalyze the regeneration rate of the spent limestone in a reducing environment. Thus both the calcium and iron components may be recycled.
TL;DR: The use of fertilizers and the leaching of basic cations from the soil by winter rain and irrigation have resulted in the acidification of soils and the need for lime applications to most crops grown in western Oregon and there is a need to examine the feasibility of reducing liming rates through partial mixing of lime with the soil.
Abstract: The use of fertilizers and the leaching of basic cations from the soil by winter rain and irrigation have resulted in the acidification of soils and the need for lime applications to most crops grown in western Oregon. As the cost of spreading lime often exceeds $20.00 per ton, there is a need to examine the feasibility of reducing liming rates through partial mixing of lime with the soil. The effects of mixing 2.2, 6.7, and 11.2 ton/ha of lime with 10, 30, 60, and 100% of the soil volume on the growth of Nugaines wheat (Triticum aestivum l.) were studied using an acid Dayton silt loam soil in a growth chamber. The soil was placed in boxes measuring 30 cm wide x 30 cm deep x 1 cm thick with the limed soil being located in equispaced vertical columns. Maximum wheat growth resulted when 6.7 ton/ha of lime was mixed with 30% of the soil. Root growth characteristics in limed and unlimed soil illustrated the chemotropic characteristics of the wheat roots with aluminum toxicity symptoms occurring in unlimed soil and where 2.2 ton/ha of lime was mixed with more than 30% of the soil. The water potential of wheatmore » plants was increased when the root growth was reduced by soil acidity.« less
Patent•
14 Dec 1978
TL;DR: In this article, the authors describe a method and apparatus for treating subsurface layers of the earth to build strength of the sub-surface layers and control the movement of the water characterized by slaking quicklime in a mixing tank.
Abstract: This specification discloses method and apparatus for treating subsurface layers of the earth to build strength of the subsurface layers and control movement of the subsurface water characterized by slaking quicklime (CaO) in a mixing tank to form an elevated temperature, hydrated lime [Ca (OH)2 ] slurry and injecting the resulting elevated temperature lime slurry at a predetermined plurality of spaced apart locations and at predetermined depths into the earth subsurface layers. This achieves a cost reduction, has greater reliability in obtaining materials, achieves better results, saves energy and extends the injection-stabilization season into cold weather previously considered prohibitive. Also disclosed are the details of preferred embodiments for admixing the unslaked lime for the various uses.
TL;DR: In this paper, a new process has been developed for wastewater purification, utilizing "Lime Sulfurated Solution" as a coagulant, which decomposes in water on contact with a gas (atmospheric air or CO2 gas) and reacts with heavy metals.
Abstract: A new process has been developed for wastewater purification, utilizing “Lime Sulfurated Solution” as a coagulant. Calcium polysulfide, the main component of this solution, decomposes in water on contact with a gas (atmospheric air or CO2 gas) and reacts with heavy metals. The heavy metals are removed as practically insoluble precipitates. The kinetics of this process were studied in a batch stirred tank vessel to obtain the fundamental data needed for development of a commercial continuous process. The findings are as follows: (1) Processing of bivalent metals Hg2+, Cd2+, Zn2+, Pb2+, and Cu2+ are completed in a few minutes to achieve the water quality standards in Japan. (2) Cr3+ is flocculated as Cr(OH)3 by the strong alkaline base of CaSx solution. It takes about 60 minutes for the precipitation with CO2 blowing, and 30 min with aeration. Cr(VI) is quickly reduced to Cr3+ and removed as Cr(OH)3. (3) A simulated wastewater simultaneously contaminated with 6 kinds of heavy metals can be brought well with...
Patent•
03 Feb 1978
TL;DR: A method of forming a chlorine tablet for combatting bacterial and algaecidal contamination of swimming pools and the like, which includes the step of pressing a mixture of calcium hypochlorite and chloride of lime, together with a minor proportion of zinc stearate as a tabletting lubricant, into a tablet was described in this paper.
Abstract: A method of forming a chlorine tablet for combatting bacterial and algaecidal contamination of swimming pools and the like, which includes the step of pressing a mixture of calcium hypochlorite and chloride of lime, together with a minor proportion of zinc stearate as a tabletting lubricant, into a tablet. The invention further relates to such a tablet.
Patent•
15 Sep 1978TL;DR: Expansive cement compositions and novel expansion agents containing free lime for use in such compositions are prepared by heating lime of particle size less than 250 microns in an atmosphere comprising water vapor at 100° to 400° C or carbon dioxide at 350° to 850° C, or by heating a partially hydrated lime at a temperature of at least 100° C as discussed by the authors.
Abstract: Expansive cement compositions and novel expansion agents containing free lime for use in such compositions. The expansion agents are prepared by heating lime of particle size less than 250 microns in an atmosphere comprising water vapor at 100° to 400° C. or carbon dioxide at 350° to 850° C., or by heating a partially hydrated lime at a temperature of at least 100° C. The encapsulated limes produced in this way are useful as expansion agents in hydratable cement compositions, the amount thereof generally being less than 30%, preferably 3 to 10%, based on the weight of the cement and additive. Cement compositions containing the novel expansion agents are useful in a wide variety of uses where shrinkage of the composition on drying has to be prevented or reduced.
TL;DR: In this article, three pioneer pasture legume species, Trifolium glomeratum, and Ornithopus compressus, were grown in a sandy soil of pH 5.0.
Abstract: Three pioneer pasture legume species,Trifolium subterraneum, Trifolium glomeratum andOrnithopus compressus, were grown in a sandy soil of pH 5.0. The growth and nodulation of each species was examined in the presence and absence of lime pelleting and with superphosphate and lime-superphosphate fertilizer. In each species tested, plant yield, nodule number and nitrogen recovery as maximal where lime pelleting and lime-super were applied together. Plant calcium indicated that the response to lime was due to changes in soil pH rather than to a calcium response.
T. glomeratum was the species most responsive to lime application but its growth was at best only half that ofT. subterraneum andO. compressus, which produced equally under both favourable (pH 5.9) and unfavourable (pH 4.4) conditions created by fertilizer applications.
Patent•
20 Jun 1978TL;DR: In this article, a calcium petroleum sulfonate containing lubricating oil is over-based using lime, carbon dioxide, a low boiling alcohol and a monoalkylbenzene solvent.
Abstract: A calcium petroleum sulfonate containing lubricating oil is overbased using lime, carbon dioxide, a low boiling alcohol and a monoalkylbenzene solvent. In one embodiment a propane-fractionated lubricating oil, calcium petroleum sulfonate, toluene, methanol and hydrated lime are treated with carbon dioxide at a temperature of about 60° C. for about 20 minutes. A resulting overbased calcium petroleum sulfonate obtained exhibited a base number of 315.
TL;DR: The effect of clove size, spacing, fertilisers, and lime on garlic (Allium sativum) was studied in a field experiment on Levin silt loam.
Abstract: The effect of clove size, spacing, fertilisers, and lime on garlic (Allium sativum) was studied in a field experiment on Levin silt loam. Treatments were: large or small cloves at 40 or 27/m2; with and without N and K; with low or high P, and lime. Best crop yield (33.9 t/ha fresh weight) resulted from large cloves at close spacing, with N and K, high P, but low lime. Fertiliser and lime need was related to Advisory soil test levels for pH and available Ca, K, P, and Mg. The range of nutrient levels, in youngest mature leaves, associated with maximum crop yield, 6.5 months after planting, was (as % dry matter): N 3.9-4.7, P 0.26-0.36, Mg 0.12-0.20, Ca 0.7-1.1, Na Nil-0.03, K 3.4-4.6, and (in ppm) Mn 50-100. Compared with 6.5 months, at 8 months leaf nutrients were lower for N, higher for Mg, Ca, Na, and Mn, with little change for P and K. From nutrient content of bulbs at harvest, crop removal was calculated to be (in kg/ha): N 201–244, S 49–64, P 28–36, Mg 5–7, Ca 17–32, Na 0.7–1.6, K 106–127, a...
01 Jan 1978
TL;DR: Lime or activated charcoal effectively reduced fluoride absorption and increased plant dry weight in lettuce (Lactuca sativa L.), perennial ryegrass (Lolium perenne L.), and spinach (Spinacia oleracca L.) grown in a fertilized perlite-peat moss medium as discussed by the authors.
Abstract: Lime or activated charcoal effectively reduced fluoride absorption and increased plant dry weight in lettuce (Lactuca sativa L.), perennial ryegrass (Lolium perenne L.), and spinach (Spinacia oleracca L.) grown in a fertilized perlite-peat moss medium. Lime in combination with charcoal surpassed that of charcoal alone in reducing fluoride absorption and increasing yields. While the addition of lime or charcoal raised the pH of the growth medium only the lime greatly reduced water-soluble fluoride. 16 references, 3 tables.
TL;DR: In this article, the effect of pozzolanas on the C 3 A hydration with and without lime and gypsum was examined and it was shown that the addition of the pozzola lowers the heat evolution caused by C 3 AH 6 hydration.
Patent•
15 Dec 1978
TL;DR: Injectable composition for desulphurizing molten ferrous metals, especially iron, comprises alkaline earth metal, preferably magnesium, and sintered mixture of lime and at least one fluxing agent as discussed by the authors.
Abstract: Injectable composition for desulphurizing molten ferrous metals, especially iron, comprises alkaline earth metal, preferably magnesium, and sintered mixture of lime and at least one fluxing agent. Magnesium is preferably 8 to 60% of composition and lime preferably is 45 to 95% of the sintered mixture. Fluxing agent is preferably alumina and fluoride. Composition enables rapid and efficient desulphurization and does not give large amounts of slag.
TL;DR: In this article, a new chemical precipitation process was developed for the removal of heavy metals and COD substances, called CaSx, which decomposes in water on contact with air or CO2 gas, and liberates H2S, CaS2O3, CaCO3 and solid sulfur particles.
Abstract: A new chemical precipitation process that had been developed for the removal of heavy metals was extended to the removal of phosphate and COD substances. For simulated wastewater contaminated with heavy metal, phosphate, and COD substances, removal experiments were undertaken in a batch, stirred vessel by using the lime sulfurated solution as a single coagulant. The coagulant, the main component of which is CaSx, decomposes in water on contact with air or CO2 gas, and liberates H2S, CaS2O3, CaCO3, CaSO4, and solid sulfur particles. While heavy metals are precipitated as metal sulfides or hydroxides, phosphate is precipitated as calcium phosphate and COD substances are sorbed on the surfaces of the precipitates and they removed. The experimental findings are as follows: (1) The simulated wastewater contaminated simultaneously with phosphate and cadmium ions can be treated better than that contaminated only with the phosphate ion. Also, the CaSx process is found to be more effective than the Ca(OH)2 process...
TL;DR: In this paper, the results of the study indicated that the resilient characteristics of the till were so greatly improved due to the addition of lime that under certain conditions, a lime stabilized layer within a pavement structure would likely fail in tension and that the material could eventually behave essentially as a granular material.
Abstract: The addition of small quantities of lime to a subgrade soil greatly improves its resistance to deformation which has been found to be extremely useful during construction under wet conditions. Soil suction, dynamic strength, and resilient characteristics of a glacial till commonly used for highway subgrade construction were studied experimentally. Changes in material properties resulting from variations in water content, lime content, confining pressure, and deviator stress intensity before and after subjecting the material to freezing and thawing were the variables considered. The results of the study indicated that the resilient characteristics of the till were so greatly improved due to the addition of lime that under certain conditions, a lime stabilized layer within a pavement structure would likely fail in tension and that the material could eventually behave essentially as a granular material.
Patent•
14 Jul 1978
TL;DR: In this article, a process for treating sponge iron to protect it against reoxidation and/or corrosion during storage and transit comprising the steps of tumbling sponge iron which is in particle form with a pre-prepared blend of caustic lime powder and an adhesion promoting additive selected from the group consisting of iron oxide or mixtures thereof with iron to produce a coated product.
Abstract: A process for treating sponge iron to protect it against reoxidation and/or corrosion during storage and transit comprising the steps of tumbling sponge iron which is in particle form with a pre-prepared blend of caustic lime powder and an adhesion promoting additive selected from the group consisting of iron oxide or mixtures thereof with iron to produce a coated product, the blend containing 1 to 20% by weight iron oxide; and then moistening the coated product with an amount of water less than the amount of water required for complete hydration of the caustic lime.
Patent•
14 Dec 1978
TL;DR: In this paper, a mixture of 50-90% fossil fuel fly ash, 10-25% by weight lime and 0-20% sand and water in a water solid ratio of 05 to 08 1-025% by- weight aluminium powder relative to the solids is then admixed, and the mixture pumped into the room or cavity for packing Pref mineral coal fly ash should be used as the chief component, or fly ash obtained from brown coal.
Abstract: Mining room packing substance which swells and finally assumes solid form is pumped into the rooms or cavities etc so as to match their outline with that of the conventional supports already installed The substance is mixed from 50-90% by weight fossil fuel fly ash, 10-25% by weight lime and 0-20% by weight sand and water in a water solid ratio of 05 to 08 01-025% by weight aluminium powder relative to the solids is then admixed, and the mixture pumped into the room or cavity for packing Pref mineral coal fly ash should be used as the chief component, or fly ash obtained from brown coal Another version of the mixture may consists of 65-75% fly ash and 25-35% sand and lime in equal amounts
Patent•
27 Jun 1978TL;DR: In this paper, an improved process for precipitating and recovering lime by reacting an aqueous solution of calcium hypochlorite with an alkaline compound is described; the pH of the resulting lime slurry is maintained in the range from about 11 to about 13.0.
Abstract: An improved process for precipitating and recovering lime by reacting an aqueous solution of calcium hypochlorite with an alkaline compound is described. The pH of the resulting lime slurry is maintained in the range from about 11 to about 13.0, whereby hemi-basic calcium hypochlorite crystals form in the slurry. When the slurry is filtered or otherwise separated to recover the lime, an improved filtration rate is obtained. In addition, washing of the lime cake to remove impurities such as sodium chloride is easily accomplished because of the ease of separating wash water in the presence of the hemi-basic calcium hypochlorite crystals.