Amounts Of Blast Furnace Slag Research Articles

A Study on the Influence of Drying and Preheating Parameters on the Roasting Properties of Limonite Pellets

In this experiment, a pellet preparation method was investigated to study the drying, preheating, and roasting properties of limonitic iron ore from a plant in Yunnan. The aim was to improve the subsequent iron-making process of limonitic iron ore and make it a substitute for sintered ore. This substitution would reduce the amount of blast furnace slag in the iron-making process. Bentonite is commonly used as a primary binder in many pelletizing plant operations. However, its excessive usage leads to a higher risk of slagging and coking in the furnace. In this paper, we aim to decrease the quantity of bentonite added, enhance the iron content in the pellets, and reduce impurities to improve the grade of limonite pellets. The results show that the optimal drying, preheating, and roasting temperatures of limonite pellets are 200 °C, 700 °C, and 1250 °C, respectively, and the optimal roasting time is 20 min, when the diameter of the pellets is 8–13 mm. The compressive strength of limonite pellets with the addition of 1.5% bentonite was the highest, meeting the demands of a general blast furnace, based on which the iron grade of limonite pellet ore was increased by 10.63%.

Engineering and Life Cycle Assessment (LCA) of Sustainable Zeolite-Based Geopolymer Incorporating Blast Furnace Slag

This study aims to investigate the preparation of zeolite-based geopolymer composites incorporating blast furnace slag at various temperatures and varying amounts of blast furnace slag as potential sustainable building and construction materials. The primary objectives were to use mining waste streams for geopolymer production and assess the mechanical behavior of these hybrid geopolymers, along with performing a life cycle assessment (LCA) to compare their environmental impact with conventional concrete. It was observed that the hybrid geopolymers attained a maximum mechanical strength of 40 MPa. Remarkably, substituting just 20% of the material with blast furnace slag resulted in a 92% improvement in compressive strength. To assess environmental impacts, a cradle-to-gate LCA was performed on different geopolymer mix designs, focusing particularly on the global warming potential (GWP). The results indicated that geopolymer concrete generated a maximum of 240 kg CO2-e/m3, which was 40% lower than the emissions from ordinary cement, highlighting the environmental advantages of geopolymer materials. Further, X-ray diffraction was used to determine the mineral composition of both raw and developed composites. Solid-state nuclear magnetic resonance (NMR) was applied to study the molecular structure changes upon incorporating blast furnace slag. The initial setting time and shrinkage of the geopolymers were also investigated. Morphological characteristics were analyzed by scanning electron microscopy (SEM). Thermal analyses confirmed the stability of the geopolymers up to 800 °C. Geopolymer composites with high thermal stability can be used in construction materials that require fire resistance. This study not only enhances the understanding of geopolymer composite properties but also confirms the substantial environmental advantages of utilizing geopolymerization in sustainable construction.

Blast furnace slag for SO2 capture: Optimization and prediction using RSM and ANN

The main reaction parameters examined were the amount of blast furnace slag, the hydration duration, ammonium acetate concentration, and temperature. The Response surface methodology was employed to quantify their impact on the sorbent's surface area. Using a central composite design, the surface area of the resulting sorbent corresponding to Brunauer-Emmett-Teller (BET) was investigated. The sorbents produced range in surface area from 49.89 to 155.33 m2/g. Additionally, the effectiveness and response prediction capacities of the Response Surface Methodology (RSM) and Artificial Neural Network (ANN) modeling methodologies were investigated. The models were assessed using various statistical metrics, including (MSE) mean squared error, (ARE) average relative errors, the (SSE) sum of squared errors, (HYBRID) Hybrid fractional error function, (SAE) Sum of the absolute errors, (R2)coefficient of determination, and Root means square. According to statistical evidence, the ANN approach surpassed the RSM-CCD model approach. The surface area of the sorbent was shown to be significantly influenced by interactions between variables in addition to all the individual variables examined. The sorbent was made from a material with substantial structural porosity based on SEM. The functional groups were identified using FTIR. The XRF determined the elemental composition of BFS-based sorbents.

Rheology of eco-friendly mortars - Effect of industrial wastes additions

– Mortar is a mixture of sand, cement, water and eventually additives. With the environmentalissues, mortars are increasingly formulated with mineral additions as a substitute for cement in order toproduce ecological mortars. It is one of the most widely used cementitious materials in the field ofconstruction and civil engineering after concrete. Mortar placement techniques are evolving day by day,such as pumping, spraying and injection. Therefore, knowing the rheological behavior of mortars becomesmore and more crucial to master their implementation techniques. This study presents the development ofa vane rheometer to estimate the plastic viscosity yield stress of mortars. The rheological parameters weredeveloped from measurements using a procedure to convert data from moment torque and rotational speedto shear stresses versus shear rate. The procedure used considered the locally sheared material as a Binghamfluid and calculated the characteristic shear rate from the quilt analogy. The device was tested with threeexperimental programs in which many rheological parameters of the compositions of different mortars werecalculated. The results obtained validated the developed rheometer test procedure and confirmed that thetest results are reproducible and repeatable. Measurements were made on different compositions of mortarof each mineral addition, altering the amount of blast furnace slag (BFS) and fly ash (FA) in order toevaluate the impact of supplemental cementitious materials and industrial wastes on the rheologicalcharacteristics (plastic viscosity and yield stress) of eco-friendly mortar..

Evaluation of the water penetration depth in mortar using water indicator and hyperspectral imaging

Water penetration is a potential cause of premature deterioration of reinforced concrete structures. The water indicator used for water detection cannot detect water penetration depths in samples containing high amount of blast furnace slag (BFS). Hence, hyperspectral imaging (HSI) was introduced in this study. Mortar specimens with different water-to-binder (w/b) ratios and BFS replacements were prepared. The moisture content distribution, water indicator, and HSI were used to measure the water penetration depth in the samples after water absorption exposure. The effects of the pore size and moisture content on the mechanisms of the water indicator were also investigated. HSI successfully detected the penetration depth of water in all mortar samples, even in those where detection by using the water indicator was not possible. The moisture content distribution and HSI yielded similar results for water penetration depths. The water penetration depths measured by applying the water indicator and HSI were similar in the mortars without BFS substitution. The water indicator underestimated the water penetration depths in the samples that contained BFS. The amount free water in the pores of mortar was the main factor controlling the applicability of the water indicator.

High value utilization of waste blast furnace slag: New Ni-CeO2/hBFS catalyst for low temperature CO2 methanation

In the steel industry, large amounts of blast furnace slag (BFS) by-products are inevitably produced and a lot of carbon dioxide is emitted. But at present, slag reuse technology has low added value. In this paper, a high value-added process using blast furnace slag to prepare catalysts for the hydrogenation of carbon dioxide to methane was proposed. Ni-CeO2/hBFS catalyst was prepared by primary wet impregnation using nitric acid modified blast furnace slag (BFS) as a support. CO2 conversion of Ni-CeO2/hBFS catalysts achieved 81.6 % at 350 °C, and the catalyst was not significantly deactivated in a 100 h stability test. The results indicate that: the addition of CeO2 improved the dispersion of Ni particles at high loadings, limited the growth of the Ni particle size and enhanced the synergy between the CO2 adsorption sites, the catalytic active sites and the support, thus improved the catalytic performance at low temperatures. This study provides an effective way for carbon dioxide emission reduction and high-value utilization of blast furnace slag, and developed a Ni-CeO2/hBFS catalyst with superior stability and catalytic performance in long-term operation, thus, the catalyst has great potential for industrial application in the carbon dioxide methanation reaction.

The Influence of the Type of Cement on the Properties of Surface Cement Concrete.

The aim of this work was to reduce the carbon footprint of cement concrete by using multi-component cement with a high content of blast furnace slag. The analysis consisted of comparing the properties of the concrete mix and the hardened concrete made of the CEM I 42.5 R-NA cement commonly used in Poland and the CEM III cement with a large amount of blast furnace slag. The tests used cement in a constant amount of 380 kg/m3, granite aggregate of 2/8, 8/16, 16/22 mm and sand of 0/2 mm. As part of this project, detailed tests of the concrete mix and hardened concrete were carried out in terms of compressive, bending, fracture and frost resistance after 150 cycles of freezing and thawing, and the pore structure in hardened concrete was assessed according to PN-EN 480-11. The endurance tests were performed after 7, 28 and 90 days. On the basis of the obtained results, it was found that the highest compressive strengths above 70.2 MPa were obtained for concrete with CEM III, 64.5 MPa for concrete with CEM I. Additionally, for concrete with multi-component cement, smaller drops in compressive strength were obtained and a more favorable pore distribution in hardened concrete was obtained. Concrete intended for road surfaces can be made of both CEM I and CEM III cement, as they meet the requirements of the technical specifications for roads with heavy traffic of heavy vehicles.

Synergistic effect of blast furnace slag on the pyrolysis process of oil-rich coal, tar product distribution and kinetic analysis

ABSTRACT Low-rank coal is used as raw material, solid waste blast furnace slag (BFS) rich in metal oxides is selected as catalyst. Co-pyrolysis experiment is carried out and explore the influence of different BFS particle size and doping amount on coal pyrolysis. The catalyst is characterized by FT-IR, XRD, TG, and the contribution degree and mechanism of BFS to the increase of oil-rich kerosene products are clarified. The results show that BFS exhibits good activity. When the added amount of BFS is 9%, the tar yield is as high as 14.65%. When the particle size is 2–5 mm, the tar yield is 14.1%. Adding BFS catalyst can improve the tar yield. By controlling the particle size and addition amount, the composition of the tar can be adjusted to achieve directional pyrolysis. According to coal kinetic analysis, when the temperature is 350–600℃, the overall activation energy in the pyrolysis process is the highest, and the first reaction is the most active.

EXPERIMENTAL STUDY ON THE SULFURIC ACID RESISTANCE OF LOW CARBON CONCRETE

In recent years, deterioration of concrete structures of sewerage facilities due to sulfuric acid attacks has been progressing. Therefore, it can be concluded that the demand for sulfur-acid resistant concrete is extremely high. In addition, concerning recent global warming countermeasures, research and development is underway on low-carbon concrete that reduced cement, which emits a large amount of carbon dioxide during the manufacturing process. The purpose of this study is to develop low carbon concrete with high sulfur-acid resistance by replacing cement with large amounts of blast furnace slag and various admixtures. As a result, it was found that the sulfur-acid resistance was improved when using blast furnace slag fine powder and fly-ash. In particular, when cement content was 20% of binder by mass, it was confirmed that the sulfur-acid resistance was excellent. What is more, there was no loss in compressive strength. It was considered that almost Ca(OH) produced by hydration reaction of cement reacted with blast furnace slag and fly-ash, so the reaction of sulfur-acid and calcium hydroxide was suppressed.

Comparison between physical–mechanical properties of mortar made with Portland cement (CEMI) and slag cement (CEMIII) subjected to elevated temperature

The use of blast furnace slag during the manufacture of cement is assumed to mitigate CO2 emissions. Generally, the amount of blast furnace slag in the slag cement (CEMIII) ranges between 36 % and 95 %. Slag cement is suitable for the production of all concrete classes, such as the large-scale civil engineering projects (roads, tunnels, bridges). In the case of tunnels, evaluating the performance of concrete exposed to high temperatures will be of great interest. This paper deals with the mechanical properties of cement pastes and mortars made with an ordinary Portland cement (CEMI) and slag cement (CEMIII) subjected to temperatures up to 650 °C. For this purpose, The test specimens were cured for 90 days and then subjected to four different temperatures (160, 300, 400 and 650 °C) at 1 °C/min. Following the 1 h of thermal load, the specimens were examined once their temperature cooled down to room temperature. Measurements were taken for mass loss, permeability, residual compressive strength and modulus of elasticity for each temperature.The test results demonstrated that permeability increases with temperature, and it follows an exponential type formula for both types of mortar. Where there is more loss of permeability in MIII mortars than in MI mortars.The residual compressive strength of all specimens increased up to 160 °C and decreased with further increase in temperature. This decrease is more significant when the temperature exceeds 400 °C. For all heating temperatures, the samples made from the slag cement (CIII and MIII) show higher residual compressive than those made with Portland cement (CI and MI). Furthermore, it was found that at all exposure temperatures the modulus of elasticity of all samples was more reduced compared to the compressive strength. In conclusion, we can say that when using slag cement, the samples show a good mechanical behavior (compressive strength and modulus of elasticity) at high temperatures and also for permeability.

Behavior of Hot-Mix Asphalt Containing Blast Furnace Slag as Aggregate: Evaluation by Mass and Volume Substitution

Significant amounts of blast furnace slag (BFS) are generated daily as by-product from iron and steel industries. This waste material usually has interesting physical properties and mineralogical and chemical composition, which can be useful as granular aggregate in the production of hot mix asphalt (HMA). In this study, an experimental program was designed to evaluate the effect on the resistance of a HMA due to the replacement (in mass and volume) of the coarse fraction of a natural aggregate (type limestone; LS) by a BFS. Total aggregate replacement was also evaluated. The mechanical properties were evaluated by carrying out the following tests: Marshall stability, indirect tensile strength (ITS), Cantabro abrasion, resilient modulus, permanent deformation, and fatigue resistance. Water sensitivity or moisture damage was evaluated by determining the ratio of indirect tensile strength (TSR) in wet and dry conditions. X-ray diffractometry (XRD), X-ray fluorescence (XRF) tests, and imaging processing in a scanning electron microscope (SEM) were carried out on particles of LS and BFS. The results revealed a remarkable enhancement in the properties of the HMA mixture when the coarse fraction of the LS was replaced in volume by BFS. When such a replacement was made in mass, the adhesive properties of the asphalt-aggregate system worsened. Total replacement of the LS led to unsatisfactory mechanical behavior.

Combined Effect of Thermal Stimulated Superplasticizer with BFS on Fresh and Hardened Property of Mortar

Usage of mineral and chemical admixtures in concrete or mortar is a usual solution to reach full compaction mainly where reinforcement blockage and the shortage of skilled labors happen. Super Plasticizers have become essential ingredients of any designed concrete mix today. Property of fresh and hardened concrete is strongly influenced by the interaction of mineral and chemical admixtures. This paper has been made to evaluate effect of heat stimulation of with two types of Polycarboxylic acid-based ether superplasticizer, pre-cast (SP2) type and ready-mix (SP1) type superplasticizer (SP) with normal Portland cement (OPC), high early strength cement (HESPC) and partially replacement of blast furnace slag (BFS) with cement 0%, 30%, 45%, and 60%. Investigated the fresh and hardened property of mortar. The superplasticizer (SP) was heated in a thermostatic chamber 70°C for 24 hours, the result shows that the heat stimulation of SP increased the fluidity, air content and flow loss, and decrease the density and compressive strength of mortar. Consequently, unitized the flow for heated and non-heated SP, and evaluate them. The air-content, density, and compressive strength were same. Besides, the flow loss was affected by many factors type of cement type of SP and heat stimulation technique of SP amount of BFS. By heat stimulation technique and increasing the amount of BFS caused to decrease the flow loss. The SP1 improve the fluidity and flow loss of mortar than SP2 in all conditions. Heat stimulation technique of SP with HESPC cement doesn’t change the fresh property of mortar. The compressive strength of HESPC was increased than OPC cement. Furthermore, by increasing the amount of BFS increased the fluidity and decreased the compressive strength and effect of heating on fluidity. The water-cement ratio was 30% and sand cement ratio was 2:1. Blast furnace slag (BFS) cause to improve the fluidity of mortar. However, by increasing the amount of BFS the compressive strength and effect of heat stimulation and flow loss was decreased.

Optimization for blast furnace slag dry cooling granulation device

Since the large accumulation amount of blast furnace slag (BFS) with recycling value, it has become a hot topic for recovery utilization. Compared with the existing various BFS granulation process, the dry granulation process can promote the use of blast furnace granulated slag as cement substitute and concrete admixtures. Our research group developed a novel dry cooling granulation experiment device to treat BFS. However, there are still some problems to be solved. The purpose of this research is to improve the cooling and granulation efficiency of the existing dry type cooling equipment. This topic uses the FLUENT simulation software to study the impact of the number of air inlet on the cooling effect of the device. The simulation result is that the device possessing eight air inlets can increase the number of hot and cold gas exchanged, resulting in a better cooling effect. According to the power consumption, LCA analysis was carried out on the cooling granulation process. The results show that the device equipped eight air inlets not only improved the original equipment cooling granulation effect, but also increased resource utilization ratio, realized energy-saving and emission reduction.

Immobilization of chromite ore processing residue with alkali-activated blast furnace slag-based geopolymer

Chromite ore processing residue (COPR) is an industrial waste produced in the chromic salts production process and contains a small portion of leached Cr(VI), which is highly toxic and is listed as a hazardous waste. The immobilization of COPR using a blast furnace slag-based geopolymer has been investigated in this study. The optimum parameters for preparing the blast furnace slag-based geopolymer using an orthogonal experiment were obtained. COPR was used to replace the amount of blast furnace slag for the preparation of the geopolymer. The COPR-bearing blast furnace slag-based geopolymer has potential application as a construction material and for geological disposal. The combined effect of physical fixation, adsorption and ion exchange in the geopolymeric and CSH (calcium silicate hydrate) gel is considered to be the main mechanism, and the reduction of S2− in the blast furnace slag played a significant role in the solidification of the COPR.

고로슬래그 미분말의 산지 및 치환율 변화가 순환잔골재 사용 시멘트 모르타르의 특성에 미치는 영향

In this study, the quality of blast furnace slag and the engineering properties of recycled aggregate based mortar with variable replacement of blast furnace slag have been focused. Blast furnace slag(BS) manufactured in various areas in Korea were prepared for this study. For the investigation results, 4 types(among the all of 9 types) of the experimental results were identified as below the standard level when using blast furnace slag chosen from different factories. Especially the particle size of the blast furnace slag was considered as the largest problem. When using BS in the recycled aggregates based mortar, the increase amount of blast furnace slag, increased the fluidity but delayed the setting time and decreased strength at early age. Based on the relationship of the amount of BS and the engineering properties of mortar, this study found that the amount of and L.O.I affect the setting time, 3 days strength and 91 days strength to the certain standard level.

Technical and economical feasibility of using GGBS in long-span concrete structures

China accounts for nearly half of the global steel production. As a waste material or a by-product in the manufacture process, a large amount of blast furnace slag is generated every year. The majority of recycled blast furnace slag is used as an additive in low-grade blended cement in China (equivalent to the UK CEM II or CEM III depending on the slag content). The cost of using ground granulated blast furnace slag (GGBS) in such low-grade applications may not be entirely reimbursed based on market research. This paper reports an on-going project at Xi\'an Jiaotong-Liverpool University (XJTLU) which investigates the feasibility of using GGBS in long-span concrete structures by avoiding/reducing the use of crack control reinforcement. Based on a case study investigation, with up to 50% of CEM I cement replaced with GGBS, a beneficiary effect of reduced thermal contraction is achieved in long-span concrete slabs with no significant detrimental effect on early-age strengths. It is believed that this finding may be transferable from China to other Asian countries with similar climates and economic/environmental concerns.

Synthesis of Zeolite from Blast Furnace Slag Using Alkali Fusion with Addition of EDTA

A large amount of blast furnace slag, a by-product of the iron-making process, is generated annually. We attempted to convert blast furnace slag (BFS) into zeolitic materials using alkali fusion with ethylenediamine tetraacetate dihydrate (EDTA) chelation. Without addition of EDTA, a mixture of hydroxysodalite and calcite was synthesized. With EDTA addition, Ca2+ ions were trapped by chelation in solution during agitation, then the chelation was promoted by heating at synthesis, and zeolite-A, zeolite-X and hydroxysodalite were synthesized.

고로슬래그 미분말과 CA계 혼합물을 사용한 압출성형패널 특성

Due to the development of steel industry, more than 12 million tons of ground granulated blast-furnace slag(GG) have produced every year. On the other hand, the amount of GG got used has been discreasing gradually due to the construction market diminished. So it is needed to develop some various usage for GG including increasing the amount of GG in concrete and concrete products. Even if the extruded panel mainly used for the external drywall having superior performance to being needed, it has not been widely utilized in the drywall market for an interior material, due to its low economic advantage. This study have checked the engineering characteristics of various extruded panels, depending on the different amounts of blast furnace slag(GG), CA binder and hemihydrate gypsum(HG), and finally determined the optimum mixture ratio of an environmentally friendly non-OPC extruded panel, with high economic and environmental feasibility. The experimental results of this study confirmed that the amount of CA could replace up to at least 10wt% of the total binder in the non-OPC extruded panel with GG in the comprehensive consideration of its strength and moldability. Then, the optimum blending ratio of alpha-hemihydrate gypsum(HG) was 20wt% of CA.

고로슬래그와 극한미생물을 이용한 모래의 고결화 연구

본 논문에서는 자원 재활용을 위해 시멘트를 전혀 사용하지 않고 잠재 수경성을 지닌 고로슬래그와 알칼리 활성화제를 이용하여 모래를 고결시키는 연구를 수행하였다. 기존 수산화칼슘이나 수산화나트륨과 같은 화학적 알칼리 활성화제뿐 아니라 pH 10 이상에서 생존하는 극한미생물을 화학적 알칼리 활성화제에 혼합한 미생물 알칼리 활성화제를 개발하여 흙의 고결 가능성을 평가하였다. 낙동강모래에 고로슬래그의 함유량을 네 종류(4, 8, 12, 16%)로 달리하면서 화학적 또는 미생물 알칼리 활성화제를 혼합하여 공시체를 제작한 다음 7일 동안 대기중 양생시킨 후 일축압축시험을 실시하였다. 알칼리 활성화제의 종류에 관계없이 고로슬래그의 함유량이 4%에서 16%로 증가함에 따라 건조밀도가 증가하면서 일축압축강도는 평균 178kPa에서 2,435kPa까지 증가하였다. 화학적 알칼리 활성화제를 사용한 경우, 수산화칼슘이 포함된 공시체의 일축압축강도가 수산화나트륨을 사용한 경우보다 5-54% 정도 높게 나타났다. 한편 본 연구에서 개발한 미생물 알칼리 활성화제를 사용한 경우, 수산화칼슘 성분이 포함된 공시체의 경우에는 화학적 알칼리 활성화제보다 일축압축강도가 11-60% 감소하였으나, 수산화나트륨이 포함된 경우에는 일축압축강도가 19-121% 증가하였다. 고결된 공시체에서 C-S-H 화합물이 생성되었으며, SEM분석에서 고로슬래그 함유량이 증가할수록 수화물의 양도 증가하였다. In this study, a blast furnace slag having latent hydraulic property with an alkaline activator for resource recycling was used to solidify sand without using cement. Existing chemical alkaline activators such as <TEX>$Ca(OH)_2$</TEX> and NaOH were used for cementing soils. An alkaliphilic microorganism, which is active at higher than pH 10, is tested for a new alkaline activator. The alkaliphilic microorganism was added into sand with a blast furnace slag and a chemical alkaline activator. This is called the microorganism alkaline activator. Four different ratios of blast furnace slag (4, 8, 12, 16%) and two different chemical alkaline activators (<TEX>$Ca(OH)_2$</TEX> and NaOH) were used for preparing cemented specimens with or without the alkaliphilic microorganism. The specimens were air-cured for 7 days and then tested for the experiment of unconfined compressive strength (UCS). Experimental results showed that as a blast furnace slag increased, the water content and dry density increased. The UCS of a specimen increased from 178 kPa to 2,435 kPa. The UCS of a specimen mixed with <TEX>$Ca(OH)_2$</TEX> was 5-54% greater than that with NaOH. When the microorganism was added into the specimen, the UCS of a specimen with <TEX>$Ca(OH)_2$</TEX> decreased by 11-60% but one with NaOH increased by 19-121%. The C-S-H hydrates were found in the cemented specimens, and their amounts increased as the amount of blast furnace slag increased through SEM analysis.

고로슬래그와 알칼리 활성화제를 이용한 모래 고결 및 조기강도에 관한 연구

본 연구에서는 자원 재활용을 위해 시멘트를 전혀 사용하지 않고 잠재 수경성을 지닌 고로슬래그를 이용하여 사질토를 고결시키고자 하였다. 알칼리 활성화제에 의해 경화되는 고로슬래그의 함유량과 알칼리 활성화제의 종류를 달리 하여 이들이 사질토의 조기강도에 미치는 영향에 대하여 연구하였다. 고로슬래그의 함유량을 사질토의 4, 8, 12, 16%로 하고 여섯 종류(두 종류의 천연재료, 네 종류의 화학약품)의 알칼리 활성화제를 사용하여 공시체를 제작하였다. 제작한 공시체는 3일 또는 7일 동안 대기중 양생한 다음 일축압축강도시험을 실시하였다. 알칼리 활성화제 종류에 따른 일축압축강도는 탄산칼륨, 수산화칼슘, 수산화나트륨, 수산화칼륨 순으로 높게 측정되었으며, 동일한 성분을 가진 천연재료보다 화학약품을 사용한 공시체의 일축압축강도가 높게 나타났다. 3일 양생한 공시체 중 최대 일축압축 강도가 발현된 것은 16%의 고로슬래그에 수산화칼륨을 사용한 경우로 3MPa 정도의 강도가 측정되었으며, 이는 초속 경시멘트 16%를 사용한 공시체 강도의 37%에 해당된다. 알칼리 활성화제 종류에 관계없이 고로슬래그 함유량이 증가함에 따라 건조밀도가 증가하면서 일축압축강도도 증가하였으며, 양생기간이 3일에서 7일로 증가함에 따라 최대 97%의 강도 증가가 발생하였다. 고결된 모래의 XRD 분석 결과 C-S-H 화합물이 생성되었으며, SEM 분석 결과에서는 고로슬래그 함유량이 증가할수록 생성되는 수화물도 증가하여 모래 입자를 에워싸는 형태를 보였다. In this study, a blast furnace slag with latent hydraulic property is used to cement granular soils without using Portland cement. When the blast furnace slag reacts with an alkaline activator, it can cement soils. The effect of amounts of blast furnace slag and types of alkaline activator on soil strength was investigated for resource recycling. Four different amounts of slag and six different activators (two naturals and four chemicals) were used for preparing specimens. The specimens were air-cured for 3 or 7 days and then tested for unconfined compressive strength (UCS). The UCS of cemented sand with slag increased, in the order of specimens mixed with potassium carbonate, calcium hydroxide, sodium hydroxide and potassium hydroxide. Chemical alkaline activator was better than natural alkaline activator. The maximum UCS of 3-days cured specimens was 3 MPa for 16% of slag with potassium hydroxide, which corresponded to 37% of one with 16% of high-early strength portland cement. As the amount of slag increased, the UCS and dry density of a specimen increased for all alkaline activator cases. As the curing time increased from 3 days to 7 days, the UCS increased up to 97%. C-S-H hydrates were found in the cemented specimens from XRD analyses. Cement hydrates were more generated with increasing amount of slag and they surrounded sand particles, which resulted in higher density.