Showing papers on "Ground granulated blast-furnace slag published in 1985"

Early high-strength mineral polymer

Abstract: An early high-strength mineral polymer composition is formed of a polysialatesiloxo material obtained by adding a reactant mixture consisting of alumino-silicate oxide (Si 2 O 5 ,Al 2 O 2 ) with the aluminum cation in a four-fold coordination, strong alkalis such as sodium hydroxide and/or potassium hydroxide, water, and a sodium/potassium polysilicate solution; and from 15 to 26 parts, by weight, based upon the reactive mixture of the polysialatesiloxo polymer of ground blast furnace slag. Sufficient hardening for demolding is obtained in about 1 hour with this composition.

Analytical Study of Pure and Extended Portland Cement Pastes: II, Fly Ash‐ and Slag‐Cement Pastes

Abstract: A range of pastes of portland cement interground with low-calcium fly ash or granulated blast furnace slag was studied by X-ray diffraction, analytical electron microscopy, thermo-gravimetry, and determinations of CO2 and of unreacted fly ash or slag. Partial replacement of clinker by fly ash results in increased reaction of the alite from at least as early as 3 d. The amount of Ca(OH)2 formed from a given weight of clinker increases at 3 d due to the enhanced reaction, but from 28 d onward, it decreases due to the pozzolanic reaction. The mean Ca/SI ratio of the C-S-H decreases with time or fly ash content, toward a lower limit of ∼1.4. Partial replacement of clinker by slag also decreases both the amount of Ca(OH)2 formed from a given weight of clinker and the mean Ca/Si ratio of the C-S-H, but to a lesser extent. Using the methods described in Part I of this paper, the results of the experimental methods were tested for mutual consistency, and volume percents of phases, porosities, and related quantities were calculated.

Cements in radioactive waste disposal: some mineralogical considerations

Abstract: Cementitious matrices are being assessed for immobilization of radioactive wastes. This paper dis- cusses some mineralogical aspects of cement chemistry and the uses of siliceous minerals as selective sorbants to enhance immobilization potential. Studies of sorption and leaching of caesium from pulverized fuel ash (PFA), blast furnace slag, tobermorite, xonotlite, and clinoptilolite are reported. The role of incorporation of these additives in cement and the effect on the nature of the composite matrix on caesium behaviour has been investigated. Specific mechanisms of the interaction of additives with highly alkaline cement environment are described. While slags, PFA, and clinoptilolite undergo reaction at different rates, tobermorite and xonotlite appear to be stable in cement. SPENT fuel elements may undergo a lengthy and complex reprocessing cycle before disposal of the resulting waste streams can be accomplished; moreover, storage, transportation, and reprocess- ing operations give rise to other waste streams. The bulk of these are non-heat generating. The esti- mated United Kingdom arisings from all sources have been estimated to the year 2000 and classified according to volume and radioactivity (Duncan and Brown, 1982). It is apparent that cement and concrete will find much application in waste disposal, mainly of non-heat generating wastes. We exclude from con- sideration its structural applications, e.g. in silos, tanks, bunkers, tunnel linings, and concentrate instead on non-structural applications, e.g. as a primary matrix for immobilization of wastes or in secondary barriers such as grouts or sealants. Cements are tolerant of water, resistant to the action of certain salts, have a long history of use and lend themselves to remote handling. Moreover, they are cheap. However, they may constitute a chemically reactive, microporous matrix and the interactions between cements and waste form, or cements and their environment, or both, have many features

The Effect of Blast Furnace Slag Cement on Alkali Aggregate Reactivity: A Literature Review

Abstract: The growing shortage of quality aggregates and the trend toward higher alkali levels in portland cement has increased the risk of problems associated with alkali-aggregate reactivity (AAR). The use of ground granulated blast furnace slag as a partial replacement for portland cement is a recognized remedial alternative in cases where a potential for AAR exists. This report reviews available literature dealing with the influence of ground granulated blast furnace slag on AAR. In general, it was concluded that when the binder consists of 50% or more of ground vitreous slag, an alkali content of up to 1.00% as sodium oxide (Na2O) equivalents can be tolerated without a risk of problems. Improved resistance to AAR was provided from slags ground to higher fineness. Several theories, promulgated to explain the mechanism for enhanced resistance to alkali reaction, are also reviewed.

Foamed cement compositions for stowing cavities

Abstract: Compositions suitable for the production of foamed cements comprise an hydraulic cement clinker (for example a mixture of ordinary Portland cement with a high alumina cement or a 12CaO.7Al2O3-rich clinker), calcium sulfate, an air-entraining or foaming agent (especially an anionic sulfate or sulfonated organic surfactant) and a stabilising agent (especially a cellulose ether). Instead of the hydraulic cement clinker, a potentially hydraulic mineral clinker may be used in the presence of an activator, for example calcium oxide and/or hydroxide. The composition may also comprise an extender (for example blast furnace slag), a clay (for example bentonite) and setting accelerators, for example inorganic salts (for example alkali metal carbonates). The compositions may be made up with water and then foamed by the introduction of a gas, for example air, the resultant foamed cement being especially useful for filling cavities in underground mines.

Hydraulic hardening material and method of manufacturing the same

Abstract: Method of manufacturing a hydraulic hardening material having the steps of milling vitreous blast furnace slag and classifying the milled slag to provide slag powder having a blaine specific surface area of 6,000 to 12,000 cm2/g. The hydraulic hardening material manufactured by the method is used as a Portland blast furnace cement raw material.

Method of producing unbaked agglomerates

Abstract: In a method of producing unbaked agglomerates, green pellets or briquettes are produced by adding 5 to 30% of reduced iron powder, mill scale powder or iron sand and also adding a binder consisting of a cement or granulated blast furnace slag and then the green pellets or briquettes are dry cured thereby producing agglomerates having excellent reducing performance.

Method for generating electric power by recovery of pressure from top of blast furnace

Abstract: PURPOSE: To remarkably increase the rate of recovery of heat by raising the temp. of blast furnace gas with heat recovered in a stage for cooling metallurgical slat at the inlet of a gas turtine, in facilities for generating electric power by the recovery of pressure from the top of a blast furnace. CONSTITUTION: Blast furnace gas BFG exhausted from a blast furnace 1 is cleaned through dust removers 2, 3, fed to a gas turbine 5 for recovering pres sure and rotates a generator 6 to generate electric power. Molten blast furnace slag S discharged from the furnace 1 is agitated, granulated and fed to a cooler 9, where the granulated slag is cooled and the sensible heat of the slag is recovered by transfer to a heat medium. This heat medium is fed to a heat exchanger 4 to raise the temp. of the blast furnace gas BFG at the inlet of the gas turbine 5. COPYRIGHT: (C)1987,JPO&Japio

Evaporation- and absorption-rate of potassium through blast-furnace slag.

Abstract: Evaporation of potassium from slag was investigated in order to estimate the effect of chemical composition and temperature The evaporation rate increased with addition of basic oxide as FeO, CaO and MgO and it decreased with addition of amphoteric oxide such as alumina and titanium dioxide Addition of MgO substituted by CaO under constant basicity B=(CaO+MgO)/SiO2 affected positively the delayed evaporation of potassium oxide

Spout refining method

Abstract: PURPOSE: To efficiency execute ≥2 kinds of preliminary refining by blasting refining agents onto the bare surface of a molten iron and blasting the next preliminary refining agents before said refining agents float on the molten iron in the case of subjecting the molten iron to ≥2 kinds of preliminary refining in blast furnace spout. CONSTITUTION: The molten iron 3 tapped from a tap hole 1a of the blast furnace 1 is poured through the blast furnace spout 4 into a torpedo 2. The molten iron 3 is subjected to preliminary refining such as desiliconizing, dephosphorizing and desulfurizing during the flow down in the blast furnace spout 6a. Blast furnace slag is discharged from a slag discharge port 4. The refining agents respectively having different properties are blasted from 3 pieces of nozzles 7a, 7b, 7c onto the bare surface of the molten iron flowing down by passing the underside of a skimmer 5a and are thoroughly penetrated into the molten iron, by which the preliminary refining is effectively executed. The 2nd refining agents of the different kind are blasted into the molten iron before the 1st refining agents blown thereto float on the surface of the molten iron. The refining agent or gas may be blasted from the final nozzle 7c. The refining agents mix thoroughly with the molten iron and ≥2 kinds of the preliminary refining are efficiently executed. COPYRIGHT: (C)1987,JPO&Japio

Leaching Behaviour of a Blast Furnace Slag Based Soil Conditioner and Liming Material

Abstract: The paper deals with the potential use of an indigenous blast furnace slag as an useful raw material for development of controlled release fertilizers as well as moderately effective liming materials.The basic composition of the blast furnace slag was changed by melting the slag with compounds of phosphorus and potassium in different proportions. It is presumed that such controlled release of phosphorus, potassium and calcium should meet the plant requirements more effectively and with less wastage. The slag base itself should have no harmful effects because of similarity of its constituents with those of the soil.Leaching studies on the rate of release of phosphorus and potassium were carried out using modified slag samples of fixed compositions and average particle size (220 μm) in aqueous medium of pH 7. The rate of release of nutrients was found to be dependent on the composition of the modified slag, and decreased with increase in slag content. A leaching study on the liming aspect of the slag was ca...

Method for desiliconizing molten iron

Abstract: PURPOSE:To perform surely desired desiliconization in a blast furnace hearth so as to deal with desiliconization and dephosphorization of a large amt. of molten iron by adding respectively desiliconizing agents to the molten iron between the tap hole on the tapping spout and skimmer of the blast furnace and between the skimmer and torpede to effect desiliconization in two stages. CONSTITUTION:The molten iron 8 discharged from a tap hole 2 of a blast furnace 1 is separated to the molten iron 8 and slag 8-2 by a skimmer 4 provided in a tapping spout 3. The molten iron 8 is fed on a molten iron spout 5 on the down stream of the skimmer 4 to a torpedo car 7. A desiliconizing agent is added to the molten iron in the spout 3 from the hole 2 to the skimmer 4 preferably at a point near the hole 2. A desiliconizing agent 9-2 is added to the molten iron 8 separated of blast furnace slag and desiliconizing slag in the skimmer 4 after the primary desiliconization prior to falling into a torpedo car 7 to execute secondary desiliconization. The reduction of (Si) in the high Si-content molten iron 8 tapped from the furnace 1 to <=0.15% required for dephosphorization of the molten iron in the blast furnace hearth is made substantially possible by such two-stages of the desiliconization treatment.

Solidifying material for use in stabilizing treatment of soft ground

Abstract: PURPOSE:To provide a solidifying material which is suitable for use in the stabilizing treatment of soft ground and has a delayed action and excellent durability, containing portland cement having a specified chemical composition and a specified particle size distribution and blast furnace slag. CONSTITUTION:A solidifying material contains 20-50wt% portland cement (A) having a 3CaO.SiO2 content of 60-70wt%, a 3CaO.Al2O3 content of 4wt% or below and a particle size distribution such that not more than 10wt% of powder is composed of particles having a particle size of 10mu or below, not more than 20wt% thereof is composed of particles having a particle size of 30mu or below and not less than 10wt% thereof is composed of particles having a particle size of 88mu or below and 50-80wt% belast furnace slag (B) in such a quantity that the combined quantity of components A and B is 100wt%. It is desirable to add not more than 2wt%, pref. 0.01-2wt% solidification-delaying agent to the solidifying material. It is preferred that blast furnace slag in the form of a powder having a ¦Blaine specific surface area of 3,500cm /g or above is incorporated in the solidifying material from the viewpoints of strength and resistance to sulfate salt and chloride.

Method of covering waste mounds using a fill

Abstract: The present invention relates to the use of a fill and ground-­ binding agent for covering waste mounds, rubbish tips and other less harmful material consisting of 1-30 % by weight cement and 99-70 % by weight waste materials selected from one or more of the following materials: fly-ash, blast furnace slag, de-­ sulphurization product, various types of other waste, such as pyrite, metal-hydroxide slag, poor ash, etc., whereby the mound first is covered with a first layer of dry materials which can be sulphate-activated by or reacted with a cement solution extract selected from one and more of fly-ash, de-sulphurization product, granulated blast-furnace slag, and which material must not be allowed to react before providing an external second layer containing a basic reserve which can be leached out such as all types of concrete, fill with more than 10 % by weight of cement and a mixture of fly-ash, and/or granulated blast-furnace slag which has been activated with de-sulphurization product and cement.

Concrete pile and its manufacture

Abstract: PURPOSE:To increase the strength of concrete piles by a method in which a concrete using a mixture of manufactured sand and blast furnace slag as fine aggregates is centrifugally compacted, preliminarily cured, and then cured in autoclave to form a concrete pile CONSTITUTION:Blast furnace slag is used as fine aggregate for concrete, and preferably water-granulated slag sand is used Manufactured sand as used as fine aggregate for usual concrete is used in combination with the blast furnace slag sand Besides the fine aggregate, cement, coarse aggregate such as crushed stone, etc, and water are used according to the proportion of the usual concrete, and a plasticizer (or water reducing agent) is also used to raise the strength of the concrete The addition of silica powder can further raise the strength of the concrete The mixture of these materials is centrifugally compacted in accordance with the manufacturing method of usual concrete pile, preliminarily cured, and then cured in autoclave

Mineral fiber composition

Abstract: PURPOSE:To provide the titled composition having improved alkali resistance, and usable as a reinforcing material for cement mortar and concrete, by adding copper oxide to a mineral fiber composition consisting of blast furnace slag and silica. CONSTITUTION:The objective mineral fiber composition is composed mainly of 40-60(wt)% SiO2, 9-13% Al2O3, 25-38% CaO, 3-5% MgO and 2-10% CuO, and is obtained by compounding 60-90% blast furnace slag with 10-40% silica and 2-10% copper oxide. The addition of silica to blast furnace slag improves the tensile strength of the fiber, and the manufacture of a continuous fiber is facilitated by increasing the amount of silica. However, too much silica lowers the alkali resistance of the fiber. The alkali resistance of the fiber can be improved remarkably by the addition of copper oxide, and the fiber added with copper oxide can be used effectively as a reinforcing material for cement mortar, concrete, gypsum product, etc.

Manufacture of nonsintered type briquetted ore

Abstract: PURPOSE: To manufacture the titled ore for blast furnace having large reposing angle, by compacting a mixture of iron ore powder, cement, coke powder, lime stone powder, water, etc., regulating water saturation ratio to a specified value, and curing said body in gaseous carbonic acid having a specified concn. CONSTITUTION: Said mixture is press compacted by roll. The green compact is regulated to ≥0.15W<0.9 water saturation ratio defined by a formula, then cured in gas contg. ≥5vol% gaseous carbonic acid. Mixture of one or ≥2 kinds among cement clinker powder, γ-2CaO.SiO 2 powder, β-2CaO.SiO 2 powder, wollastonite powder, blast furnace slag powder, steel making slag powder, slaked lime powder can be used for substitution of cement. By this way, the titled ore having large reposing angle and preventing segregation phenomenon during feeding it into blast furnace, is manufactured. COPYRIGHT: (C)1986,JPO&Japio

Destruction material composition

Abstract: PURPOSE:To provide a composition which hardens simultaneously with the start of expansion and has improved destruction capability, by adding a small amount of a mixing agent to a mixture containing coarse particles of granulated blast furnace slag having a specific coarse granule content and an specific amount of an expansion material composed of a powdery clinker containing a large amount of CaO CONSTITUTION:The objective composition is produced by compounding (A) 100ptswt of a mixture composed of (i) 30-95ptswt of an expansion material composed of powdery clinker having CaO content of >=30% (eg calcia clinker, CaO-3CaOSiO2-CaSO4 clinker, etc having an average crystal size of preferably 10-100mu) and (ii) 5-70ptswt of coarse particles of granulated blast furnace slag having a coarse particle ratio of 05-35 with (B) 005-5ptswt of a mixing agent (eg sucrose, glucose beta-naphthalenesulfonic acid-formaldehyde condensate, etc)

Binder for starting material to be sintered

Abstract: PURPOSE: To obtain an inexpensive binder for granulating starting materials for a blast furnace by adding silicate-base rock, a mineral or the like to molten steel making slag, rapidly cooling the resulting product, and adding a stimulant for hardening CONSTITUTION: At least one among silicate-base rock, a mineral, efflorescence, slag, glass scraps, waste mineral sand, coal ash, waste brick, red mud, ejecta, blast furnace slag, desulfurization slag and iron oxide is added to molten steel making slag, and they are brought into a reaction in a molten state The resulting product is rapidly cooled, dried and crushed, and a small amount of a stimulant for hardening such as gypsum, lime, CaO, Ca(OH) 2 or cement is added to obtain a binder which gives sintered ore of high quality when used for granulation COPYRIGHT: (C)1986,JPO&Japio

Solidifying agent for soft ground

Abstract: PURPOSE:To provide the titled solidifying agent which is inexpensive, can be effectively used for long-term operation such as treatment of large blocks or ground to be deeply improved and can sufficiently joint ground to be freshly treated to ground already treated, by incorporating calcium phosphate as a retarder in cement CONSTITUTION:A solidifying agent for soft ground, particularly for use in a deep layer mixing treatment method is obtd by incorporating a calcium phosphate-contg material such as tricalcium phosphate, calcium hydrogen-phosphate, calcium superphosphate or fused phosphate fertilizer as a retarder in a mixed cement such as blast furnace slag cement or portland cement such as normal or rapid-hardening portland cement This solidifying agent contg the solidification- retarding agent can be effectively used for long-term operation such as treatment of ground to be deeply improved large blocks of ground to be jointed, can sufficiently joint ground to be freshly treated to ground already treated, and has further advantages in that the retarder is inexpensive and curing time can be arbitrarily controlled by the quantity of the retarder

Fuel coal for converter and its preparation

Abstract: PURPOSE:To prepare fuel coal which is dense, has a high initial strength and a thermal efficiency equal to that of lump coke and can be brought to a high temp. quickly, by mixing specified dust coke with blast furnace slag in powder and forming the mixt. into shape by press molding. CONSTITUTION:100pts.wt. dust coke having a particle diameter of 8mm. or smaller, of which moisture content and distribution of particles of 3mm. in diameter have been determined beforehand, and 20-100pts.wt. dust coal are fed from receiving hoppers 1, 1' on belt feeders 2, 2' and moisture content is adjusted to 6- 12wt% on a shaking sieve 3. Particles on and under the sieve are crushed in a roll crusher 5 and, after particle size adjustment in such a way that particles smaller than 3mm. in diameter may account for 80wt% or higher, the crushed coal is temporarily stored in a sub-hopper 4 for intermittent supply to a mixer 6 in predetermined amts. 10-40pts.wt. blast furnace slag in powder (c) and 0.8- 4wt% binder (d) are fed into the mixer through a hopper 7, a feeder 8 and a weighter 10 and the mixt. (e) is pressed into shape continuously in a double- roll press 11 to produce formed fuel coal. The formed fuel coal is carried on a net conveyor 12 for storage in a bin 13.

Breaking agent incorporated with blast furnace slag for brittle matter

Abstract: PURPOSE:To obtain titled agent capable of gradually and linearly developing expansive force, also with ultimate high-level expansivity, by incorporating blast furnace slag powder in a pulverized sintered matter prepared from calcareous material containing iron compound. CONSTITUTION:First (A) 100pts.wt. of a pulverized sintered matter prepared from a calcareous material containing, in the post-calcination stage, iron compound so as to be 0.1-25wt% on a Fe2O3 basis is blended, if required, with (B) /g thus obtaining the objective breaking agent. EFFECT:Easy to set processing condition, also with good workability when processed. Furthermore, capable of developing expansive force at any rate according to regulating its components.

Taking out of molten iron from rock wool raw material melt

Abstract: PURPOSE: To make it possible to continuously carry out rock wool production operation, by providing a perforable blocking mud in the sidewall of the lowermost part in a furnace on the opposite side of the outflow port of the melt with respect to the center of a smelting furnace and perforating the mud at an optional time to take out the stored molten iron. CONSTITUTION: Blast furnace slag is charged through a charging inlet 4 into the body of an electric furnace 1 and a preheated component adjusting material is then charged from a charging pipe 8 to adjust a raw material melt 17. The furnace body is tilted by hydraulic cylinders 15 and pistons 16 to continuously feed the raw material melt 17 through an outflow port 9 to a fiber machine 10 and produce the aimed rock wool. In the process, iron and iron oxide in the slag are reduced into molten iron 18, which is gradually stored in the lower- most part of the furnace 1 to reach the height of the outflow port 9. Therefore a perforable blocking mud perforable by a perforating machine 19 is provided in the sidewall of the lower- most part of the furance 1 on the opposite side to the outflow port 9 to perforate the mud by the perforating machine 19 for each given amount of the molten slag. The furnace body 1 is tilted to take out the stored molten iron 18. Thereby the operation can be subsequently transferred to fiber making operation without adversely affecting the continuous fiber making operation. COPYRIGHT: (C)1987,JPO&Japio

Slag cement - low-level waste forms at the Savannah River Plant

Abstract: A cement based waste form is being designed for disposal of Savannah River Plant low-level radioactive waste salt. The disposal process includes emplacing the saltstone in engineered trenches. The waste form (matrix) must exhibit reasonable physical/mechanical properties with minimal leaching of the contained waste salts (1). As part of a program carried out at PSU/MRL to optimize properties of the waste form (2), formulations containing low-calcium fly ash and granulated blast furnace slag with and without portland cement have been tested and the data compared with those of other mixes containing either low- or high-calcium fly ash and no slag. The results of physical/mechanical testing, leach tests, chemical characterization, and adiabatic heat of hydration are presented. Included is a review of the alkali-activated slag hydration process. 12 refs., 21 figs., 10 tabs.

The composition of hydraulic cement

Abstract: High-strength hydraulic cement has the following composition: blast furnace slag (60-85%), anhydrous or bihydrous gypsum (5-15%), pozzolan matter (6-12%), calcium hydroxide (2-10%), portland cement clinker or portland cement (1-6%), and siliceous fluorides (0.5-3%). The compositions are ground finely at 2500-4600 cm2/gr, and mixed. This hydraulic cement does not need a sintering process because it uses blast furnace slag as a raw material.