JP6844600B2 - Method and device for removing selenium from slag, reuse method for slag, and manufacturing method for recycled slag - Google Patents
Method and device for removing selenium from slag, reuse method for slag, and manufacturing method for recycled slag Download PDFInfo
- Publication number
- JP6844600B2 JP6844600B2 JP2018211878A JP2018211878A JP6844600B2 JP 6844600 B2 JP6844600 B2 JP 6844600B2 JP 2018211878 A JP2018211878 A JP 2018211878A JP 2018211878 A JP2018211878 A JP 2018211878A JP 6844600 B2 JP6844600 B2 JP 6844600B2
- Authority
- JP
- Japan
- Prior art keywords
- slag
- selenium
- solid
- liquid mixture
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000002893 slag Substances 0.000 title claims description 157
- 239000011669 selenium Substances 0.000 title claims description 101
- 229910052711 selenium Inorganic materials 0.000 title claims description 99
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 title claims description 97
- 238000000034 method Methods 0.000 title claims description 48
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 239000007788 liquid Substances 0.000 claims description 40
- 239000000203 mixture Substances 0.000 claims description 32
- 239000011575 calcium Substances 0.000 claims description 29
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 28
- 229910052791 calcium Inorganic materials 0.000 claims description 28
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 28
- 238000002156 mixing Methods 0.000 claims description 23
- 239000007791 liquid phase Substances 0.000 claims description 22
- 239000000126 substance Substances 0.000 claims description 20
- 239000003814 drug Substances 0.000 claims description 19
- 229940079593 drug Drugs 0.000 claims description 19
- 229910000288 alkali metal carbonate Inorganic materials 0.000 claims description 10
- 150000008041 alkali metal carbonates Chemical class 0.000 claims description 10
- 238000010438 heat treatment Methods 0.000 claims description 9
- 238000005406 washing Methods 0.000 claims description 7
- 238000000926 separation method Methods 0.000 claims description 6
- 238000003756 stirring Methods 0.000 claims description 5
- 229910019142 PO4 Inorganic materials 0.000 claims description 4
- 229910052783 alkali metal Inorganic materials 0.000 claims description 4
- 150000001340 alkali metals Chemical class 0.000 claims description 4
- 235000021317 phosphate Nutrition 0.000 claims description 4
- 150000004649 carbonic acid derivatives Chemical class 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 150000003013 phosphoric acid derivatives Chemical class 0.000 claims description 3
- 230000001376 precipitating effect Effects 0.000 claims description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims description 2
- 238000010298 pulverizing process Methods 0.000 claims description 2
- 239000002994 raw material Substances 0.000 claims description 2
- 238000003860 storage Methods 0.000 claims description 2
- 150000003467 sulfuric acid derivatives Chemical class 0.000 claims description 2
- 238000012546 transfer Methods 0.000 claims description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 claims 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims 1
- 239000000654 additive Substances 0.000 claims 1
- 230000000996 additive effect Effects 0.000 claims 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical class OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 claims 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims 1
- 239000010452 phosphate Substances 0.000 claims 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 24
- 229910000831 Steel Inorganic materials 0.000 description 18
- 239000010959 steel Substances 0.000 description 18
- 229910000029 sodium carbonate Inorganic materials 0.000 description 12
- 235000017550 sodium carbonate Nutrition 0.000 description 12
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 8
- 229910052717 sulfur Inorganic materials 0.000 description 8
- 239000011593 sulfur Substances 0.000 description 8
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 7
- 229910001424 calcium ion Inorganic materials 0.000 description 7
- 238000006477 desulfuration reaction Methods 0.000 description 7
- 230000023556 desulfurization Effects 0.000 description 7
- 238000010828 elution Methods 0.000 description 6
- 230000007613 environmental effect Effects 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 238000007670 refining Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 230000003009 desulfurizing effect Effects 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 239000007790 solid phase Substances 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- -1 and at the same time Chemical compound 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 159000000007 calcium salts Chemical class 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical class [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Description
本発明は、有害なセレンを含有するスラグを処理してセレンを除去する方法及び装置並びにセレン除去後のスラグの再利用方法および再生スラグの製造方法に関するものである。 The present invention relates to a method and an apparatus for treating slag containing harmful selenium to remove selenium, a method for reusing slag after removing selenium, and a method for producing recycled selenium.
鋼材品質に対する要求水準の高度化に伴い、鋼中の燐や硫黄、水素等の不純物や、アルミナ等の非金属介在物の含有量を下げることが必要となってきている。製鋼プロセスでは、前述のような不純物等を除去するための精錬処理が行われるが、それぞれの不純物処理の過程で副産物であるスラグが発生する。鉄鋼スラグは、生成過程で１２００〜１４００℃以上の高温を経るため、有機化合物や水銀、ヒ素、カドミウム等の低沸点の重金属はほとんど含まれず、溶出試験で検出もされない。そのため、ＪＩＳ規格「ＪＩＳ Ａ５０１５：２０１３（道路用鉄鋼スラグ）」では、環境項目として鉛、六価クロム、セレン、フッ素、ホウ素の５物質を規定している。その溶出量基準は土壌の汚染に係る環境基準（平成３年環境庁告示第４６号）（以下、「土壌環境基準」という。）と同等である。 With the sophistication of the required level for steel quality, it has become necessary to reduce the content of impurities such as phosphorus, sulfur and hydrogen in steel and non-metal inclusions such as alumina. In the steelmaking process, the refining treatment for removing impurities and the like as described above is performed, but slag, which is a by-product, is generated in each impurity treatment process. Since steel slag undergoes a high temperature of 1200 to 1400 ° C. or higher in the production process, it contains almost no organic compounds or heavy metals having a low boiling point such as mercury, arsenic, and cadmium, and is not detected in the elution test. Therefore, the JIS standard "JIS A5015: 2013 (steel slag for roads)" stipulates five environmental items: lead, hexavalent chromium, selenium, fluorine, and boron. The elution amount standard is equivalent to the environmental standard for soil contamination (Notification No. 46 of the Environmental Agency, 1991) (hereinafter referred to as "soil environmental standard").
鉄鋼スラグの中には、硫黄を含有するスラグがあるが、これは、鉄鋼製造プロセスにおける製錬工程や精錬工程で、溶銑または溶鋼中の硫黄などの不純物をスラグに移行させて吸収させているためである。例えば、高炉で発生する高炉スラグ、とりわけ高炉で発生する溶融スラグを冷却ヤードで徐冷した高炉徐冷スラグや、脱硫剤を用いて溶銑の脱硫を行なう際に発生する脱硫スラグ、あるいは低硫鋼を製造するために脱炭後の溶鋼に行なう脱硫工程で発生する二次精錬スラグなどは、比較的多くの硫黄を含有している。硫黄を含有する鉄鋼スラグでは、その同族元素であるセレンが含まれ、基準値を超えるセレンが溶出する可能性がある。そこで、特に硫黄を含む鉄鋼スラグのセレン溶出量を、基準値以下にまで抑制する方法が求められている。 Among steel slag, there is slag containing sulfur, which is absorbed by transferring impurities such as sulfur in hot metal or molten steel to the slag in the smelting process and refining process in the steel manufacturing process. Because. For example, blast furnace slag generated in a blast furnace, especially molten slag generated in a blast furnace is slowly cooled in a cooling yard, desulfurized slag generated when desulfurizing hot metal with a desulfurizing agent, or low sulfurized steel. Secondary refining slag generated in the desulfurization process performed on the molten steel after decarburization for the production of blast furnace contains a relatively large amount of sulfur. Sulfur-containing steel slag contains selenium, which is a homologous element thereof, and selenium exceeding the standard value may elute. Therefore, in particular, there is a demand for a method of suppressing the amount of selenium elution from steel slag containing sulfur to below a standard value.
スラグ以外では、例えば特許文献１では様々な薬剤を用いてセメント製造工程で発生する塩素バイパスダストからセレンを除去する技術が提案されている。しかしながら、スラグからセレンを除去する技術はこれまで開示されていなかった。
In addition to slag, for example,
しかしながら、特許文献１をスラグに適用しようとする場合に、スラグと塩素バイパスダストとでは組成が大きく異なるため、特許文献１のような方法を適用するのは難しい。一方で、鉄鋼業におけるスラグの再利用にはセレンの除去が必要となっているにも拘らず、その方法は確立していない。
However, when applying
本発明は、かかる事情に鑑み鋭意検討の結果なされたもので、スラグ（特に硫黄を含むスラグ）に含まれるセレンを除去することによって、該スラグの再利用を推し進めることを目的とするものである。 The present invention has been made as a result of diligent studies in view of such circumstances, and an object of the present invention is to promote the reuse of slag by removing selenium contained in slag (particularly slag containing sulfur). ..
本発明は、スラグに含まれるセレンを取り除く方法に関して、スラグに水を加えるとスラグに１０〜５０質量％程度含まれるカルシウムが水に溶出し、液相のカルシウムイオンを除去することでスラグからのセレン溶出が促進する現象に着目してスラグからセレンを除去することを特徴とする。 The present invention relates to a method for removing selenium contained in slag. When water is added to slag, calcium contained in slag in an amount of about 10 to 50% by mass is eluted in water, and calcium ions in the liquid phase are removed to remove calcium ions from the slag. It is characterized by removing selenium from slag by focusing on the phenomenon that selenium elution is promoted.
以下は、セレンを含むスラグとして溶銑脱硫処理で発生する脱硫スラグを例に説明するが、セレンを含むスラグであれば同様の挙動によりセレンを除去することができる。図１は、粉砕した脱硫スラグに純水を加えて固液混合物とし、この固液混合物に炭酸ナトリウムを一定量ずつ添加し濾過したときの液相中のカルシウム濃度と固相（脱硫スラグ）中のセレン除去率の変化を示したグラフである。図１に示すように、本発明者らは、脱硫スラグ中のセレン除去率とカルシウム濃度には相反する関係、すなわち液相中のカルシウムが減少するほど脱硫スラグからセレンが除去されることを見出した。この現象を解明するために、本発明者らはさらにカルシウムとセレンの挙動を調査した。脱硫スラグ中にはＣａＯが含まれているため、脱硫スラグを水中に分散するとＣａＯが溶解してカルシウムイオンとなり、アルカリ性を呈する。この段階では脱硫スラグ中のセレンは液相にわずかな量しか溶出しなかった。この水溶液に炭酸ナトリウムを添加すると、液相のカルシウムイオンが炭酸カルシウムとして沈殿し始め、それと同時に脱硫スラグ中のセレンが液相に溶出し始めることがわかった。カルシウムイオンを沈殿させることにより、脱硫スラグからの脱セレンを進行させることが可能である。この方法を用いることにより、脱硫スラグ中のセレンを約４０％程度除去できることがわかった。本発明者らはさらに高いセレン除去率を目指して鋭意検討を重ねた。 Hereinafter, desulfurized slag generated in the hot metal desulfurization treatment as slag containing selenium will be described as an example, but selenium can be removed by the same behavior as long as it is slag containing selenium. FIG. 1 shows the calcium concentration in the liquid phase and the solid phase (desulfurized slag) when pure water is added to the crushed desulfurized slag to form a solid-liquid mixture, and sodium carbonate is added in a fixed amount to the solid-liquid mixture and filtered. It is a graph which showed the change of the slag removal rate of. As shown in FIG. 1, the present inventors have found that the relationship between the selenium removal rate in the desulfurized slag and the calcium concentration is contradictory, that is, the selenium is removed from the desulfurized slag as the calcium in the liquid phase decreases. It was. To elucidate this phenomenon, we further investigated the behavior of calcium and selenium. Since CaO is contained in the desulfurized slag, when the desulfurized slag is dispersed in water, CaO is dissolved to become calcium ions, which are alkaline. At this stage, only a small amount of selenium in the desulfurized slag was eluted in the liquid phase. It was found that when sodium carbonate was added to this aqueous solution, calcium ions in the liquid phase began to precipitate as calcium carbonate, and at the same time, selenium in the desulfurized slag began to elute into the liquid phase. By precipitating calcium ions, it is possible to proceed with deselenium from desulfurized slag. It was found that about 40% of selenium in the desulfurized slag can be removed by using this method. The present inventors have made extensive studies aiming at a higher selenium removal rate.
図１で、脱硫スラグから液相中に溶出するセレン量が一定に達するまで炭酸ナトリウムを添加した固液混合物を、加熱しながら脱硫スラグからのセレン除去率の変化を調査した。図２に、固液混合物温度に対する脱硫スラグからのセレン除去率の変化を示す。固液混合物温度の上昇とともにセレン除去率は増加し、６０℃で約６０％、さらに１００℃で９０％以上のセレンを除去できることがわかった。なお、一旦加熱して常温に戻った固相中のセレン濃度が増えることはなかった。 In FIG. 1, the change in the selenium removal rate from the desulfurized slag was investigated while heating the solid-liquid mixture to which sodium carbonate was added until the amount of selenium eluted from the desulfurized slag into the liquid phase reached a certain level. FIG. 2 shows the change in the selenium removal rate from the desulfurized slag with respect to the temperature of the solid-liquid mixture. It was found that the selenium removal rate increased as the temperature of the solid-liquid mixture increased, and about 60% of selenium could be removed at 60 ° C., and 90% or more of selenium could be removed at 100 ° C. The selenium concentration in the solid phase, which was once heated and returned to room temperature, did not increase.
本発明は上記知見に基づくものであり、特徴は以下の通りである。
［１］スラグを粉砕する粉砕工程と、
粉砕された前記スラグを水と混合して固液混合物とする混合工程と、該固液混合物に薬剤を添加して前記スラグに含まれるセレンを液相に移行させる脱セレン工程と、
前記スラグと薬剤水溶液とを分離する固液分離工程とを有する、スラグからセレンを除去する方法。
［２］前記粉砕工程において粉砕された前記スラグは最大直径で２ｍｍ以下の大きさである、［１］に記載のスラグからセレンを除去する方法。
［３］前記混合工程において、混合する水の量が前記スラグの質量の等倍以上である［１］または［２］に記載のスラグからセレンを除去する方法。
［４］前記脱セレン工程において添加する薬剤がアルカリ金属炭酸塩である、［１］乃至［３］のいずれかに記載のスラグからセレンを除去する方法。
［５］前記脱セレン工程において薬剤水溶液を加熱する、［１］乃至［４］のいずれかに記載のスラグからセレンを除去する方法。
［６］前記脱セレン工程において薬剤水溶液の加熱温度が６０℃以上である、［５］に記載のスラグからセレンを除去する方法。
［７］前記脱セレン工程において添加する薬剤の制御を前記固液混合物の液相中のカルシウム濃度に基づいて行なう、［１］乃至［６］のいずれかに記載のスラグからセレンを除去する方法。
［８］前記脱セレン工程の後、前記スラグを沈殿槽で沈降させ、次いで水洗してアルカリ金属を取り除く水洗工程を有する、［１］乃至［７］のいずれかに記載のスラグからセレンを除去する方法。
［９］スラグと水を混合し撹拌して固液混合物とする混合槽と、
この混合槽中の固液混合物に薬剤を添加するための薬剤貯留槽と、
薬剤添加終了後の固液混合物を貯留しスラグを沈降させるための沈殿槽と、
を備えるスラグからセレンを除去する装置。
［１０］前記薬剤がアルカリ金属炭酸塩である、［９］に記載のスラグからセレンを除去する装置。
［１１］更に、混合槽中の液相のカルシウム濃度を測定するためのカルシウム分析装置を備える［９］または［１０］に記載のスラグからセレンを除去する装置。
［１２］沈降させたスラグを水洗するためのポンプと、固液分離装置をさらに設ける［９］乃至［１１］のいずれかに記載のスラグからセレンを除去する装置。
［１３］さらに混合槽に固液混合物を加熱するためのヒーターと温度計を設ける［９］乃至［１２］のいずれかに記載のスラグからセレンを除去する装置。
［１４］［１］乃至［８］のいずれかに記載の方法でセレンが除去された前記スラグを原料として、路盤材用途において再利用するスラグの再利用方法。
［１５］［１］乃至［８］のいずれかに記載の方法でスラグ中のセレンを除去して、該スラグを再利用可能とする再生スラグの製造方法。
The present invention is based on the above findings, and its features are as follows.
[1] A crushing process for crushing slag and
A mixing step of mixing the crushed slag with water to form a solid-liquid mixture, and a de-selenium step of adding a chemical to the solid-liquid mixture to transfer selenium contained in the slag to a liquid phase.
A method for removing selenium from slag, which comprises a solid-liquid separation step for separating the slag and an aqueous chemical solution.
[2] The method for removing selenium from the slag according to [1], wherein the slag crushed in the crushing step has a maximum diameter of 2 mm or less.
[3] The method for removing selenium from the slag according to [1] or [2], wherein the amount of water to be mixed is equal to or more than the mass of the slag in the mixing step.
[4] The method for removing selenium from the slag according to any one of [1] to [3], wherein the chemical added in the selenium removal step is an alkali metal carbonate.
[5] The method for removing selenium from the slag according to any one of [1] to [4], wherein the aqueous chemical solution is heated in the selenium removal step.
[6] The method for removing selenium from the slag according to [5], wherein the heating temperature of the aqueous chemical solution is 60 ° C. or higher in the selenium removal step.
[7] The method for removing selenium from the slag according to any one of [1] to [6], wherein the chemical added in the selenium removal step is controlled based on the calcium concentration in the liquid phase of the solid-liquid mixture. ..
[8] The selenium is removed from the slag according to any one of [1] to [7], which comprises a water washing step of sedimenting the slag in a settling tank and then washing with water to remove the alkali metal after the selenium removal step. how to.
[9] A mixing tank that mixes slag and water and stirs them to form a solid-liquid mixture.
A drug storage tank for adding chemicals to the solid-liquid mixture in this mixing tank,
A settling tank for storing the solid-liquid mixture after the addition of the chemical and for sedimenting the slag,
A device that removes selenium from slag.
[10] The device for removing selenium from the slag according to [9], wherein the drug is an alkali metal carbonate.
[11] Further, the apparatus for removing selenium from the slag according to [9] or [10], which comprises a calcium analyzer for measuring the calcium concentration of the liquid phase in the mixing tank.
[12] The device for removing selenium from the slag according to any one of [9] to [11], further providing a pump for washing the settled slag with water and a solid-liquid separation device.
[13] The device for removing selenium from the slag according to any one of [9] to [12], further providing a heater and a thermometer for heating the solid-liquid mixture in the mixing tank.
[14] A method for reusing slag that is reused in a roadbed material application using the slag from which selenium has been removed by the method according to any one of [1] to [8] as a raw material.
[15] A method for producing recycled slag, which removes selenium in the slag by the method according to any one of [1] to [8] so that the slag can be reused.
本発明のスラグからの脱セレン方法に従ってスラグを処理すれば、該スラグ中のセレンを十分に除去することが可能となるので、鉄鋼製造工程で発生するスラグが環境基準を逸脱する心配なく、スラグを処理することができる。 If the slag is treated according to the method for removing selenium from the slag of the present invention, the selenium in the slag can be sufficiently removed, so that the slag generated in the steel manufacturing process does not deviate from the environmental standard. Can be processed.
本発明で対象とするスラグは、セレンを含有することによりセレン除去が必要なスラグ（セレン濃度が１質量ｐｐｍ超のスラグ）であれば特に限定されるものではないが、高炉または溶銑もしくは溶鋼の脱硫工程で発生する硫黄を含むスラグはセレンを含有しやすく、高炉スラグ（とりわけ高炉徐冷スラグ）並びに溶銑脱硫処理で発生する脱硫スラグおよび溶鋼脱硫処理で発生する二次精錬スラグは本発明の対象として効果的である。 The slag targeted in the present invention is not particularly limited as long as it contains slag and requires slag removal (slag having a slag concentration of more than 1% by mass ppm), but is not limited to that of blast furnace, hot metal or molten steel. Slag containing sulfur generated in the desulfurization process tends to contain slag, and blast furnace slag (particularly blast furnace slow cooling slag), desulfurization slag generated in hot metal desulfurization treatment, and secondary refining slag generated in molten steel desulfurization treatment are the objects of the present invention. It is effective as.
図３は本発明の実施形態に係る装置の一例を示す図である。本発明であるスラグからセレンを除去する方法について、図３に基づき説明する。高炉または溶銑もしくは溶鋼の脱硫工程で発生するスラグを粉砕工程で粒状に粉砕した後、スラグホッパ２に貯留され、混合槽１に適量が投入される。粉砕後のスラグの粒子サイズは、液相との反応界面積が大きくなるように、最大直径２ｍｍ以下が好ましく、２ｍｍ目の篩を通過したスラグを用いればよい。混合槽１はポンプ３と流量計４を介して槽内に注水できる構造となっており、スラグ投入と同時に、あるいは直後にポンプ３と流量計４を介して水が混合槽１に注入され、槽内が撹拌されて、スラグが固液混合物となる。次いで該固液混合物に、薬剤ホッパ５に貯留された薬剤が混合槽１内の固液混合物に少しずつ添加される。
FIG. 3 is a diagram showing an example of an apparatus according to an embodiment of the present invention. The method for removing selenium from slag according to the present invention will be described with reference to FIG. After the slag generated in the desulfurization step of the blast furnace, hot metal or molten steel is crushed into granules in the crushing step, it is stored in the
混合槽１に注入する水の量は、スラグの質量の等倍以上とする。注入する水の量がスラグの質量の等倍未満では、スラリーを形成できず脱Ｓｅが不十分となるだけでなく、プロセス途中での詰まりなどの原因となる。注入する水の量は、スラグの質量の２倍以上が好ましい。注入する水の量は、スラグ質量の１００倍以下が好ましい。スラグの質量の１００倍超えでは、スラグからのカルシウムの溶出が増え、Ｃａを沈殿除去しスラグから十分に脱Ｓｅさせるために、薬剤の添加量を多くしなければならないためである。
The amount of water injected into the
添加する薬剤は、カルシウムを沈殿させることができる薬剤が利用でき、薬剤の種類としては、例えば炭酸塩、炭酸水素塩、リン酸塩、硫酸塩、亜硫酸塩などが挙げられる。中でも溶解度の低いカルシウム塩を形成できるリン酸塩や炭酸塩が好適で、さらに溶解度が高く取扱いの容易なアルカリ金属炭酸塩が最適である。アルカリ金属炭酸塩としては、炭酸リチウム、炭酸ナトリウム、炭酸カリウムなどがあるが、特に炭酸ナトリウムはソーダ灰として安価に入手できることからより好適である。コストの面からも使用するアルカリ金属炭酸塩の量を低減することが望ましい。そこで、本発明の装置では、カルシウム分析装置６により、液相中のカルシウムイオンの量を測定し、測定結果に応じて添加するアルカリ金属炭酸塩の溶解を調節することでアルカリ金属の混入を最小化することができる。液相のカルシウムイオン量を測定するためのカルシウム分析装置６は、原子吸光法、ＩＣＰ発光分析法などが利用できる。 As the drug to be added, a drug capable of precipitating calcium can be used, and examples of the drug type include carbonates, bicarbonates, phosphates, sulfates, sulfites and the like. Of these, phosphates and carbonates that can form calcium salts with low solubility are preferable, and alkali metal carbonates that have high solubility and are easy to handle are most suitable. Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, potassium carbonate and the like, but sodium carbonate is particularly preferable because it can be obtained inexpensively as soda ash. From the viewpoint of cost, it is desirable to reduce the amount of alkali metal carbonate used. Therefore, in the apparatus of the present invention, the amount of calcium ions in the liquid phase is measured by the calcium analyzer 6, and the dissolution of the alkali metal carbonate to be added is adjusted according to the measurement result to minimize the mixing of alkali metals. Can be transformed into. As the calcium analyzer 6 for measuring the amount of calcium ions in the liquid phase, an atomic absorption method, an ICP emission spectrometry method, or the like can be used.
カルシウム分析装置６による液相中のカルシウム濃度の分析と、この結果に基づく薬剤の添加を繰り返し行ない、液相中からカルシウムが検出されなくなったら（即ち、カルシウムの検出量が０．０１ｍｇ／ｍｌ以下になったら）、薬剤の添加を終了する。なお、図３では液相中のカルシウム濃度に基づいて添加する薬剤を制御する方法について説明したが、処理開始前のスラグの段階で測定したカルシウム濃度とスラグ量から液相中へ溶出するカルシウム濃度を推定して、薬剤添加量を求めることもできる。この状態の固液混合物を沈殿槽７に送液することもできるが、さらに混合槽１に設けたヒーター１１と温度計１０で固液混合物（薬剤水溶液）を好ましくは６０℃以上、より好ましくは１００℃以上に加熱してから該固液混合物を沈殿槽７に送液する。このように固液混合物を加熱することで、セレンの除去率を高めることができる。ヒーター１１としては電気加熱方式やマイクロ波加熱方式、バーナー加熱方式などが利用できる。
Analysis of the calcium concentration in the liquid phase by the calcium analyzer 6 and addition of a drug based on this result are repeated, and when calcium is no longer detected in the liquid phase (that is, the amount of calcium detected is 0.01 mg / ml or less). When it becomes), the addition of the drug is finished. Although the method of controlling the drug to be added based on the calcium concentration in the liquid phase was described in FIG. 3, the calcium concentration measured at the slag stage before the start of the treatment and the calcium concentration eluted into the liquid phase from the amount of slag. Can also be estimated to determine the amount of drug added. The solid-liquid mixture in this state can be sent to the settling tank 7, but the solid-liquid mixture (chemical aqueous solution) is preferably 60 ° C. or higher, more preferably 60 ° C. or higher, with the heater 11 and the
薬剤添加後のスラリーのｐＨは、１１．０〜１３．５であることが好ましい。 The pH of the slurry after the addition of the chemical is preferably 11.0 to 13.5.
以上により、スラグに含まれるセレンを液相に移行させて脱セレンした後の固液混合物は、混合槽１から沈殿槽７に送液し、沈殿槽７で沈降させる。次いで、沈降したスラグにポンプ８を介して洗浄水を注入してアルカリ金属分を水洗してから、固液分離装置９でスラグと薬剤水溶液に固液分離する。固液分離装置９は、プレスフィルターや遠心分離機などが利用できる。以上のようにして、脱硫スラグから実質的にセレンを含まない再利用可能なスラグ（セレン濃度１質量ｐｐｍ以下）を得ることができる。
As described above, the solid-liquid mixture after selenium contained in the slag is transferred to the liquid phase and deselenium is removed is sent from the
再利用先は必ずしも限定されるものではないが、鉄鋼スラグの再利用先として路盤材用などが代表的な用途である。本発明で得られる再生スラグはセレン濃度がセレン溶出量の環境基準０．０１ｍｇ／Ｌ以下を満たすことのできるレベル（セレン濃度１質量ｐｐｍ以下）まで低減できるので、再利用は一般の鉄鋼スラグと同様の方法で行なうことができる。 The reuse destination is not necessarily limited, but a typical use as a reuse destination for steel slag is for roadbed materials. Since the regenerated slag obtained by the present invention can reduce the selenium concentration to a level (selenium concentration of 1 mass ppm or less) that can satisfy the environmental standard of 0.01 mg / L or less of the selenium elution amount, it can be reused with general steel slag. It can be done in the same way.
以下、実施例として、セレンを含む脱硫スラグをアルカリ金属炭酸塩で脱セレン処理した事例を用いて説明する。 Hereinafter, as an example, a case in which desulfurized slag containing selenium is desulfurized with an alkali metal carbonate will be described.
図３の装置を模擬したラボ装置を用いて実験を行なった。セレンを約４質量ｐｐｍ含有する脱硫スラグ５０ｇに純水５００ｍｌを添加した固液混合物を撹拌しながら、薬剤として炭酸ナトリウムを添加した。一度に添加する炭酸ナトリウム量を０．５ｇとし、添加毎に固液混合物を採取してろ過したうえで、ろ液中のカルシウム濃度を原子吸光法で測定した。カルシウムの濃度を確認しながら炭酸ナトリウムの添加を繰り返すと、４回の添加つまり２ｇを添加したところでカルシウムの濃度が０．０１ｍｇ／ｍｌとなったので薬剤添加を完了した。この時のスラグを分析するとセレン濃度は約１質量ｐｐｍであった。続いて、固液混合物が１００℃に達するまで加温して脱セレン工程での処理を完了した。さらに固液混合物を沈殿槽７に移し、沈降したスラグをプレスフィルター９で水洗してから固液分離した。最終的に回収した脱硫スラグ中のセレン濃度は、０．１質量ｐｐｍ以下と大幅に低減することができた。 An experiment was conducted using a laboratory device simulating the device shown in FIG. Sodium carbonate was added as a chemical while stirring a solid-liquid mixture in which 500 ml of pure water was added to 50 g of desulfurized slag containing about 4 mass ppm of selenium. The amount of sodium carbonate added at one time was 0.5 g, and after each addition, a solid-liquid mixture was collected and filtered, and then the calcium concentration in the filtrate was measured by atomic absorption spectroscopy. When the addition of sodium carbonate was repeated while checking the calcium concentration, the calcium concentration became 0.01 mg / ml when 4 times of addition, that is, 2 g was added, so that the drug addition was completed. Analysis of the slag at this time revealed that the selenium concentration was about 1 mass ppm. Subsequently, the solid-liquid mixture was heated until it reached 100 ° C. to complete the treatment in the selenium removal step. Further, the solid-liquid mixture was transferred to the settling tank 7, and the settled slag was washed with water with a press filter 9 and then solid-liquid separated. The concentration of selenium in the finally recovered desulfurized slag could be significantly reduced to 0.1 mass ppm or less.
以下、実施例として、セレンを含む脱硫スラグをアルカリ金属炭酸塩で脱セレン処理した事例を用いて説明する。 Hereinafter, as an example, a case in which desulfurized slag containing selenium is desulfurized with an alkali metal carbonate will be described.
容器を７つ用意し、セレンを約４質量ｐｐｍかつカルシウムを約３５質量％含有する脱硫スラグを５０ｇ秤量して各容器に入れ、各容器に純水を２５ｍｌ、５０ｍｌ、１００ｍｌ、２５０ｍｌ、５００ｍｌ、１０００ｍｌ、５０００ｍｌをそれぞれ添加した。容器の内容物を撹拌しながら、薬剤として炭酸ナトリウム１０ｇを添加した。３時間後に撹拌を停止して固液分離し、回収したスラグ中のセレン濃度を分析した。結果を表１に示す。表１に示すように、スラグ量の０．５倍以下の水量の条件ではセレンの除去がやや劣る結果であった。 Seven containers were prepared, 50 g of desulfurized slag containing about 4 mass ppm of selenium and about 35 mass% of calcium was weighed and put into each container, and 25 ml, 50 ml, 100 ml, 250 ml, 500 ml of pure water were added to each container. 1000 ml and 5000 ml were added respectively. While stirring the contents of the container, 10 g of sodium carbonate was added as a drug. After 3 hours, stirring was stopped, solid-liquid separation was performed, and the selenium concentration in the recovered slag was analyzed. The results are shown in Table 1. As shown in Table 1, the removal of selenium was slightly inferior under the condition of the amount of water 0.5 times or less the amount of slag.
１ 混合槽
２ スラグホッパ
３ ポンプ
４ 流量計
５ 薬剤ホッパ
６ カルシウム分析装置
７ 沈殿槽
８ ポンプ
９ 固液分離装置
１０ 温度計
１１ ヒーター
１２ 処理済スラグ
1
Claims (15)
粉砕された前記スラグを水と混合して固液混合物とする混合工程と、該固液混合物に薬剤を添加して前記スラグに含まれるセレンを液相に移行させる脱セレン工程と、
前記スラグと薬剤水溶液とを分離する固液分離工程とを有し、
前記脱セレン工程において添加する薬剤が炭酸塩、炭酸水素塩、リン酸塩、硫酸塩、亜硫酸塩のいずれか１種である、スラグからセレンを除去する方法。 The crushing process to crush the slag and
A mixing step of mixing the crushed slag with water to form a solid-liquid mixture, and a de-selenium step of adding a chemical to the solid-liquid mixture to transfer selenium contained in the slag to a liquid phase.
Possess a solid-liquid separation step of separating the slag and the drug solution,
Said additive to drug carbonates in the de selenium process, hydrogen carbonates, phosphates, sulfates, Ru any one Tanedea sulfite, a method for removing selenium from the slag.
この混合槽中の固液混合物に炭酸塩、炭酸水素塩、リン酸塩、硫酸塩、亜硫酸塩のいずれか１種である薬剤を添加するための薬剤貯留槽と、
薬剤添加終了後の固液混合物を貯留しスラグを沈降させるための沈殿槽と、
を備えるスラグからセレンを除去する装置。 A mixing tank that mixes slag and water and stirs to make a solid-liquid mixture.
A drug storage tank for adding a drug which is any one of carbonate, hydrogen carbonate, phosphate, sulfate, and sulfite to the solid-liquid mixture in this mixing tank.
A settling tank for storing the solid-liquid mixture after the addition of the chemical and for sedimenting the slag,
A device that removes selenium from slag.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018050823 | 2018-03-19 | ||
| JP2018050823 | 2018-03-19 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2019162610A JP2019162610A (en) | 2019-09-26 |
| JP6844600B2 true JP6844600B2 (en) | 2021-03-17 |
Family
ID=68065352
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2018211878A Active JP6844600B2 (en) | 2018-03-19 | 2018-11-12 | Method and device for removing selenium from slag, reuse method for slag, and manufacturing method for recycled slag |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6844600B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113912024B (en) * | 2021-10-22 | 2024-03-22 | 昆明理工大学 | Method for removing impurity sulfur from selenium-sulfur slag |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5549375B2 (en) * | 2010-05-25 | 2014-07-16 | Ｊｆｅスチール株式会社 | Desulfurization slag treatment method, desulfurization flux manufacturing method, desulfurization slag continuous use method, and desulfurization slag treatment apparatus |
| JP5988018B2 (en) * | 2011-08-05 | 2016-09-07 | 学校法人 芝浦工業大学 | Metal recovery method in cement manufacturing process |
| KR101329673B1 (en) * | 2011-10-27 | 2013-11-15 | 한국지질자원연구원 | Enhancement of carbonation efficiency from the blast furnace slag |
| JP2015123393A (en) * | 2013-12-26 | 2015-07-06 | 株式会社ネオス | Method and system for extracting and removing heavy metals in soil |
| US20190078170A1 (en) * | 2016-03-24 | 2019-03-14 | Nisshin Steel Co., Ltd. | Method for eluting calcium from steel slag and method for recovering calcium from steel slag |
-
2018
- 2018-11-12 JP JP2018211878A patent/JP6844600B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2019162610A (en) | 2019-09-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20080056982A1 (en) | Process for recycling waste acid | |
| KR102094398B1 (en) | Method of recycling chlorine bypass dust generated in cement manufacturing process | |
| KR101789701B1 (en) | Manufacturing method of potassium chloride using cement bypass dust | |
| CN114127319A (en) | Method for recovering target metal from iron or steel slag using at least one of carbothermic process and pyrometallurgical-hydrometallurgical process | |
| JP6844600B2 (en) | Method and device for removing selenium from slag, reuse method for slag, and manufacturing method for recycled slag | |
| JP2007532773A (en) | Steel production methods | |
| JP2015124388A (en) | Manufacturing method of zinc oxide ore | |
| JP5904089B2 (en) | Method for producing zinc oxide ore | |
| JP6089792B2 (en) | Steelmaking slag treatment method | |
| CA2704450C (en) | Process for recycling spent pot linings (spl) from primary aluminium production | |
| FI124666B (en) | A method and system for removing fluoride from sulfate solutions | |
| CN106676275A (en) | Vanadium extraction method based on waste steel slag and acid-base property waste water | |
| JP6848952B2 (en) | Method and equipment for removing selenium from sintered dust, reuse method for sintered dust, and manufacturing method for recycled dust | |
| JP2005255485A (en) | Method for producing phosphorous silicate fertilizer and apparatus therefor | |
| CA2192084C (en) | Hydrometallurgical treatment for the purification of waelz oxides through lixiviation with sodium carbonate | |
| JP2002285255A (en) | Method for manufacturing zinc oxide calcine or zinc oxide briquette | |
| RU2459879C2 (en) | Method of making pellets for reduction casting | |
| JP2009240952A (en) | Waste treatment method | |
| EA016467B1 (en) | Method of radium stabilization in solid effluent or effluent containing substances in suspension | |
| JP2016011924A (en) | Radioactive cesium separation enrichment method and radioactive cesium separation enrichment device | |
| JP2005305244A (en) | Treating method of substance containing heavy metals | |
| US20240010516A1 (en) | Valorization of Waste Streams | |
| JP6349166B2 (en) | Operation method of radioactive cesium separation and concentration equipment | |
| WO2003018850A1 (en) | Method in the manufacture of steel | |
| JP2002332529A (en) | Method for removing fluorine from crude zinc oxide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20190327 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20191025 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20200722 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20200818 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20201012 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20210126 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20210208 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6844600 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |