Sıra | DOSYA ADI | Format | Bağlantı |
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01. | Application Sequestration Application Plates | pptx | Sunumu İndir |
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POTENTIAL VALORIZATIONS OF ARTIFICIAL GYPSUM GENERATED IN THE MANUFACTURE OF TITANIUM DIOXIDE PIGMENTS S.M. Pérez-Moreno, M.J. Gázquez, J.P. Bolívar Group of Radiations Physics and Environment, University of Huelva, Huelva, Spain.World Congress and Expo on Recycling July 20-22, 2015 Barcelona ll l1E-mail address: silviamaria.perez@alu.uhu.es
CONTENT INTRODUCTION OBJECTIVES MATERIALS AND METHODS RESULTS AND DISCUSSION WASTE CHARACTERIZATION APPLICATIONS 1 APPLICATIONS 2 FINAL REMARKS2
INTRODUCTION3 Globally huge amounts of inorganic industrial wastes are generated and their management represents a high cost and an environmental problem. The development of technologies and new applications to valorize these wastes is of increasing importance. The factory of Tioxide-Huelva is the only one in Spain devoted to the TiO2 production. Two residues, red gypsum (RG) and un-attacked ilmenite mud (MUD) have been studied.
INDUSTRIAL PROCESS4RED GYPSUM(CaSO4·2H2O)NEUTRALIZATIONILMENITE (FeTiO3) iCLARIFICATIONPRECIPITATIONFILTER AND WASHDIGESTION CALCINATIONTiO2H2SO4Weak acid streamMUD70.000 tons per year30.000 tons per yearCurrently these wastes have no commercial value and are disposed of in an authorized and controlled repository area
OBJECTIVES1. Use of RG and MUD as building materials for fire-resistant panels.2. Use of RG as a calcium source for carbon dioxide sequestration.5
6CHARACTERIZATION METHODS X-Ray fluorescence (XRF) X-Ray difraction (XRD) Inductively coupled plasma-mass spectrometry (ICP-MS) Granulometry analysis Thermogravimetric analysis (TGA) Scanning electron microscopy (SEM-EDS)
7MATERIALS MUD and RG samples were collected every 5 days for 1 month, in order to evaluate the possible temporal variability of the characteristics of these material In order to carry out the applications studied in this work, several materials as Pladur, vermiculite and NaOH were used.
RESULTS AND DISCUSSION8 WASTE CHARACTERIZATION APPLICATIONS 1 APPLICATIONS 2
MUD AND RED GYPSUM9WASTE CHARACTERIZATION
10SiO2 18±1Al2O3 2.5±0.2FeO(T) 11±1MnO 0.36±0.01MgO 0.38±0.02CaO 0.75±0.01SO3 6.1±0.7TiO2 53±1ZrO2 4.2±0.1Concentration (%) of major elements by XRF SEM analysis of MUD and their X-ray spectraMineralogical composition by XRD: ilmenite (FeTiO3), rutile (TiO2), Zircon (ZrSiO4), Quartz (SiO2)Mineral phases are highly refractoryMUDGranulometry ~ 40 µm
11 20 µm SEM analysis of RG and their X-ray spectraSiO2 1.2±0.2Al2O3 1.4±0.2FeO(T) 14±2MnO 0.35±0.04MgO 1.4±0.2CaO 33±2SO3 27±1TiO2 7.6±1.2Concentration (%) of major elements by XRFMineralogical composition by DRX: Gypsum (CaSO4·2H2O) and iron and titanium oxides RED GYPSUMGranulometry ~ 60 µm
RG and MUD as building materials for fire-resistant panels12APPLICATION 1
13Code RG MUD VermiculitePlate 1 100 % - -Plate 2 75 % 25% -Plate 3 80% 15% 5%Plates were made using a low cost manufacturing method:o The components were mixed with water, in different percentages.o The pastes obtained were poured into a 25 x 25 cm by 2.8 cm thick molds and were dried for 25 days at ambient temperature. Vermiculite was used to increase the insulating capacity of plates.Pladur (R) was used as typical building material.
14The fire-resistance capacity was evaluated in agreement to EN-1363-1 standard, which established a temperature (T) versus the time (t) inside an oven by the equation: T = 20+345· log10(8t+1), where T is the internal temperature (°C), and t is the time (minutes) from the beginning of the test.The experiment is finished when:o The temperature of one of the thermocouples on the non-exposed surface of the material is above 180 ºC.o The average temperature of all the thermocouples on the non-exposed surface is above 140 ºC + Tenv (environmental temperature).FIRE-RESISTANCE TESTS
15Plates 1–3: similar insulating behavior, much better than Pladur®. The addition of mud improves thermal insulation significantly, mainly due to its highly refractory mineral phases. (Plate 2 and 3 better than 1)The influence of vermiculite on the material is negligible.exposed surface
CONCENTRATION VALUES (ΜG/L) OF LEACHABILITY OF TRACE ELEMENTS FROM THE PLATES AND LIMITS VALUES OF TCLP TEST .16 As Cd Co Se Cr Cu Ni Pb Sr V ZnPlate 2 <1 <1 5.2±0.4 <11.7±0.225.7±1.842±5 <1336±11<139±3Plate 3 <1 1.9±0.18.5±0.5 <12.1±0.247.2±2.268±3 <1330±10<171±4U.S. EPA 5000 1000 -1000 5000 - -5000 - - -The leaching test shows a metals concentration lower than regulatory limits by EPA for TCLP test.
RG as a calcium source for carbon dioxide sequestration.17APPLICATION 2
18CARBONATION PROCESSTheoretical Global Reaction:CaSO4·2H2O (s) + 2 NaOH(aq) + CO2 (g) CaCO3 (s) + Na2SO4 (aq) +H2O (RG) CaSO4·2H2O (s)NaOH + H2ONa2SO4 (aq)+ H2O CaCO3 (s)CO2Tº = 75ºC, P= atm
19RG Carbonated fraction Sulphate fractionSiO2 0.74±0.05 1.2±0.1 (103±11) 0.35±0.03 (38±4)Al2O3 0.75±0.02 1.0±0.1 (84±8) 0.04±0.01 (4.4±1.1)Fe2O3 7.3±2.0 9.0±2.5 (79±30) 0.03±0.01 (0.34±0.15)MnO 0.25±0.07 0.30±0.08 (76±29) 0.01±0.01 (3.3±3.4)MgO 0.77±0.05 0.30±0.02 (25±2) 0.95±0. 06 (101±9)CaO 28±2 47±3 (106±10) 1.8±0.1 (5.3±0.5)Na2O 0.18±0.01 0.50±0.03 (0.84±0.07)37±3 (80±8)K2O 0.03±0.01 0.04±0.01 (84±35) 0.01±0.0 1 (27±20)TiO2 3.8±0.1 4.7±0.1 (79±3) 0.02±0.010 (0.43±0.21)P2O5 0.05±0.01 0.05±0.01 (64±18) 0.01±0.01 (17±17)SO3 34±1 2.1±0.1 (4.0±1.0) 35±1 (85±4)Concentration (%) of major elements and the transfer factor (%) in the brackets
20132Carbonated sample (C1)123SEM analysis and their corresponding X-ray spectra Thermogravimetric analysis resultsParticles present a poorly developed rectangular shape which is characteristic of calcite (CaCO3)Mineralogical composition by XRD: Calcite (CaCO3) and rutile (TiO2).
CO2 SEQUESTRATION EFFICIENCY (CE)21Where:X exp ~ calcium in form of carbonate generated in the processX theo ~ total calcium in the red gypsumCE = 92 ± 6 %
CONCLUSIONS22
23APPLICATION 1: USE OF RG AS BUILDING MATERIALS FOR FIRE-RESISTANT PANELS Fire-resistance Test demonstrate that the plates perform better than some materials used in construction such as Pladur®. The tested material also possesses acceptable mechanical properties that showed no noticeable distortion or breakage during the test. Although, the mechanical properties of plates must be study. Also, it was conducted leaching tests using the TCLP procedure and results showed a negligible environmental impact.
24APPLICATION 2: USE OF RG A CALCIUM SOURCE FOR CARBON DIOXIDE SEQUESTRATION The products of RG carbonation, using NaOH as extracting agents, are: CaCO3 and Na2SO4.The pollutants remain almost completely into the carbonation fraction, whereas the sulphate fraction is very clean. The environmental implications of both of them are negligible for future applications.The carbonation efficiency obtained is very high under experimental conditions.
FINAL REMARKSo This study was carried out to evaluate the use of RG as building materials for fire-resistant panels and a calcium source for carbon dioxide sequestration, owing to its high content of Ca.o Previously, it was necessary an exhaustive characterization of raw materials and later, a study of new materials obtained or products was made. o Preliminary results show that these residues are viable in the studied applications. o And the environmental implications are considered as negligible.25
THANK YOU FOR YOUR ATTENTION Group of Radiations Physics and Environment, University of Huelva, Huelva, Spain.World Congress and Expo on Recycling July 20-22, 2015 Barcelona ll l26E-mail address: silviamaria.perez@alu.uhu.es