JPH0453600B2 - - Google Patents
Info
- Publication number
- JPH0453600B2 JPH0453600B2 JP59076749A JP7674984A JPH0453600B2 JP H0453600 B2 JPH0453600 B2 JP H0453600B2 JP 59076749 A JP59076749 A JP 59076749A JP 7674984 A JP7674984 A JP 7674984A JP H0453600 B2 JPH0453600 B2 JP H0453600B2
- Authority
- JP
- Japan
- Prior art keywords
- sludge
- wastewater
- phosphoric acid
- production
- 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.)
- Expired - Lifetime
Links
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 47
- 239000002351 wastewater Substances 0.000 claims description 36
- 239000010802 sludge Substances 0.000 claims description 32
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 19
- 238000006386 neutralization reaction Methods 0.000 claims description 18
- 238000004519 manufacturing process Methods 0.000 claims description 17
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 10
- 238000001914 filtration Methods 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 239000002367 phosphate rock Substances 0.000 claims description 8
- 238000000354 decomposition reaction Methods 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 6
- 239000013505 freshwater Substances 0.000 claims description 4
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims description 3
- 229910001424 calcium ion Inorganic materials 0.000 claims description 3
- 239000000498 cooling water Substances 0.000 claims description 2
- 239000007788 liquid Substances 0.000 claims description 2
- 239000012266 salt solution Substances 0.000 claims 1
- 238000005406 washing Methods 0.000 claims 1
- 239000002912 waste gas Substances 0.000 claims 1
- 239000012535 impurity Substances 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 3
- 229910001634 calcium fluoride Inorganic materials 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 239000012267 brine Substances 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 235000021317 phosphate Nutrition 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 229910001392 phosphorus oxide Inorganic materials 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000013049 sediment Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- VSAISIQCTGDGPU-UHFFFAOYSA-N tetraphosphorus hexaoxide Chemical compound O1P(O2)OP3OP1OP2O3 VSAISIQCTGDGPU-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/18—Phosphoric acid
- C01B25/22—Preparation by reacting phosphate-containing material with an acid, e.g. wet process
- C01B25/222—Preparation by reacting phosphate-containing material with an acid, e.g. wet process with sulfuric acid, a mixture of acids mainly consisting of sulfuric acid or a mixture of compounds forming it in situ, e.g. a mixture of sulfur dioxide, water and oxygen
- C01B25/223—Preparation by reacting phosphate-containing material with an acid, e.g. wet process with sulfuric acid, a mixture of acids mainly consisting of sulfuric acid or a mixture of compounds forming it in situ, e.g. a mixture of sulfur dioxide, water and oxygen only one form of calcium sulfate being formed
- C01B25/225—Dihydrate process
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Removal Of Specific Substances (AREA)
- Treatment Of Sludge (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
Description
【発明の詳細な説明】
本発明は、リン鉱石を硫酸で湿式分解する事に
よりリン酸を製造する際に生じる廃水の処理法に
関し、その場合リン鉱石分解の際に生じるセツコ
ウスラツジは液状で捨場に堆積される。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating wastewater generated during the production of phosphoric acid by wet decomposition of phosphate rock with sulfuric acid. Deposited.
リン酸、リン鉱石から熱的および湿式分解法に
より製造される。リン酸の世界生産高の約10％を
しめる熱的方法では、リン鉱石をケイ酸およびコ
ークスを用いて電気抵抗炉中で高温で分解し、そ
の場合生じる元素状リンを燃焼して酸化リン、殊
にP4O10にし、これを引続き加水分解してリン酸
を得る。これとは異なり、リン酸の世界生産高の
約90％をしめる湿式法では、リン鉱石を鉱酸、殊
に硫酸で分解する。この場合硫酸で湿式分解の
際、リン鉱石中に含まれているカルシウムはいわ
ゆるリン酸セツコウ（CaSO4・xH2Ｏ）として沈
殿する。通常リン酸製造工程の終わりにセツコウ
スラツジの形で生じるこのリン酸セツコウは、そ
の中に含有されている不純物のために直ちに他の
利用に供することは出来ない。このためには、む
しろまず生じるセツコウスラツジをさらに精製す
る事が必要であるが、これは多くの場合経済的理
由から断念される。湿式リン酸製造の際生じるセ
ツコウスラツジを引続き使用することが規定され
ていない限り、これは今日では特に次のような方
法で除去される：
１ セツコウスラツジを場合により相応に希釈し
た後、海中へポンプで送入する。 Phosphoric acid, produced from phosphate rock by thermal and wet decomposition methods. The thermal method, which accounts for about 10% of the world's production of phosphoric acid, involves decomposing phosphate rock with silicic acid and coke at high temperatures in an electric resistance furnace, and burning the resulting elemental phosphorus to produce phosphorus oxide, In particular, P 4 O 10 is obtained, which is subsequently hydrolyzed to give phosphoric acid. In contrast, the wet process, which accounts for about 90% of the world's production of phosphoric acid, breaks down phosphate rock with mineral acids, particularly sulfuric acid. In this case, during wet decomposition with sulfuric acid, the calcium contained in the phosphate rock precipitates as so-called phosphate slag (CaSO 4 .xH 2 O). This phosphoric acid sludge, which usually occurs in the form of sludge at the end of the phosphoric acid production process, cannot be immediately put to other uses due to the impurities contained therein. For this purpose, it is rather necessary to further purify the resulting sludge, which is often abandoned for economic reasons. Unless the continued use of the sludge resulting from wet phosphoric acid production is specified, it is nowadays removed inter alia in the following way: 1. Pumping the sludge into the sea, possibly after diluting it accordingly. Send.
２ セツコウを、セツコウスラツジを相応に乾燥
した後、乾燥状態で堆積する。2. Deposit the sludge in a dry state after drying the sludge accordingly.
３ セツコウスラツジを液状で堆積する。3. Deposit sludge in liquid form.
これらの３つの方法のうち、実際には最後に挙
げられたものが最も多く使用される。しかし、こ
の方法の著しい欠点は、セツコウスラツジに付着
する工程廃水が強い酸性でありかつ不純物、特に
多量のフツ化物およびリン酸塩を含有する事に見
られる。それゆえ、この廃水を直ちに排水溝中へ
投棄する事も出来ない。さらに、セツコウスラツ
ジ堆積所の漏洩箇所から出る、制御されずに流出
する廃水により地下水の汚染が惹起されるという
危険が生じる。 Of these three methods, the last one is used most often in practice. However, a significant drawback of this process is that the process wastewater adhering to the sludge is strongly acidic and contains impurities, especially large amounts of fluorides and phosphates. Therefore, it is not possible to immediately dump this wastewater into a drainage ditch. Furthermore, there is a risk that groundwater contamination may be caused by the uncontrolled discharge of wastewater from the leakage points of the Setsukou sludge dump.
従つて本発明の課題は、冒頭に挙げられた種類
の方法において、セツコウスラツジ堆積物から流
出する廃水の適当な処理を配慮する事であり、本
発明によればこの廃水を適当な方法で再使用し、
それにより該廃水の排水溝中への廃棄ならびに他
の環境汚染が避けられる。 It is therefore an object of the invention to take into account, in a method of the type mentioned at the outset, a suitable treatment of the wastewater flowing out from the Setsukou Sludge deposit, which according to the invention can be reused in a suitable manner. death,
Disposal of the waste water into drains as well as other environmental pollution is thereby avoided.
この課題の解決に役立つ方法は、本発明によれ
ば特許請求の範囲第１項の方法特徴ａ〜ｄの適用
を特徴とする。 A method which serves to solve this problem is characterized, according to the invention, by the application of method features a to d of claim 1.
本発明による方法の詳細は、特許請求の範囲第
２項〜第４項から明らかであり、次に図面に示さ
れたフローシートにつき説明する。この場合フロ
ーシートは、この目的のために無条件に必要な方
法工程のみを示す。前接されたリン酸製造装置の
詳細は、フローシートには示されていない。しか
しながら、リン酸製造ならびにフローシートに示
された全ての工程は、このために一般に常用の機
械および装置を用いて実施することから出発する
事が出来る。フローシートは同時に１実施例の説
明に役立つ。この場合、セツコウスラツジ堆積所
１から流出する廃水は、主に不純物としてＦ，
SO4，P2O5およびSiO2を有する。 Details of the method according to the invention emerge from the claims 2 to 4 and will now be explained with reference to the flow sheet shown in the drawing. In this case, the flow sheet shows only those process steps which are absolutely necessary for this purpose. Details of the foregoing phosphoric acid production equipment are not shown in the flow sheet. However, the phosphoric acid production and all the steps shown in the flow sheet can proceed from being carried out using machines and equipment generally customary for this purpose. The flow sheet also serves to illustrate one embodiment. In this case, the wastewater flowing out from the Setsuko Slatsuji Depository 1 mainly contains F,
Contains SO 4 , P 2 O 5 and SiO 2 .
この廃水は1.2〜2.0のPH値を有し導管２により
第１中和工程３に導入され、ここでカルシウムイ
オンの添加により2.5〜4.5PH値にもたらせる。こ
の場合、廃水中に存在するフツ素含有成分の約99
％がフツ化するカルシウムとして沈殿する。この
フツ化カルシウム富有スラツジは、第１中和工程
３から４で取り出され、スラツジの除去された廃
水は導管５により第２中和工程６に導入される。
ここで廃水は、カルシウムイオンをさらに添加す
る事により９〜13のPH値にもたらされる。それに
より、殊になお廃水中に存在するP2O5含量は約
95％減少し、ならびにSiO2含量は約90％減少す
る。この際生じるスラツジは再び廃水から分離
し、７で第２中和工程６から取り出される。第２
中和工程６から出る後処理されかつスラツジを除
去した廃水は次の不純物を有するにすぎない：
Ｆ＜10ppm
P2O5＜30ppm
SiO2＜150ppm
この場合驚いた事に、本発明による互いに分離
された２つの工程での中和によつて、この中和を
たんに１工程で実施する場合よりも著しく良好な
廃水浄化効果が得られる事が判明した。浄化され
た廃水は導管８によつてリン酸濾過工程９に戻さ
れ、ここで洗浄水として再使用される。もちろ
ん、この手段によりリン酸濾過工程における清水
需要は相応に低下する。 This wastewater has a PH value of 1.2 to 2.0 and is introduced via line 2 into a first neutralization step 3, where it is brought to a PH value of 2.5 to 4.5 by addition of calcium ions. In this case, approximately 99% of the fluorine-containing components present in the wastewater
% precipitates as calcium fluoride. This calcium fluoride-rich sludge is removed in the first neutralization step 3 to 4, and the waste water from which the sludge has been removed is introduced via a conduit 5 into the second neutralization step 6.
Here the wastewater is brought to a pH value of 9-13 by further addition of calcium ions. Thereby, in particular the P 2 O 5 content still present in the waste water is approximately
95% reduction, as well as the SiO 2 content by about 90%. The sludge produced in this case is again separated from the waste water and removed at 7 from the second neutralization step 6. Second
The after-treated and de-sludged wastewater leaving the neutralization stage 6 has only the following impurities: F<10ppm P 2 O 5 <30ppm SiO 2 <150ppm In this case, surprisingly, the separation from each other according to the invention It has been found that the two-step neutralization provided provides a significantly better wastewater purification effect than when the neutralization is carried out in just one step. The purified waste water is returned via conduit 8 to the phosphoric acid filtration step 9 where it is reused as wash water. Of course, by this measure the fresh water demand in the phosphoric acid filtration process is correspondingly reduced.
４および７で第１および第２中和工程から取り
出されるスラツジはまとめて共通の機械的脱水工
程１０に供給する事が出来、ここで70重量％より
少ない残存含水量にまで脱水される。これに引続
き、スラツジはたとえは噴霧乾燥機またはドラム
乾燥機として構成されていてもよい乾燥工程１１
に入り、この中でスラツジの完全な乾燥が行なわ
れる。この際生じる乾燥物質は１２で取り出さ
れ、たとえばフツ化水素酸の製造のための装入物
質として添加することが出来る。熱い乾燥機排ガ
スは、導管１３により取り出され、熱交換器１４
中で導管８中の処理された廃水を加熱するのに利
用される。即ち、洗浄媒体として使用される処理
された廃水は＞30℃の温度を有する場合、リン酸
濾過工程９における洗浄効果は著しく改良出来る
事が判明した。フローシートにおいては、第１お
よび第２中和工程からのスラツジが一緒に引続き
処理されるようになつている。しかし、このスラ
ツジを互いに別個に処理する事ももちろん可能で
ある。これは殊に、第１中和工程からのフツ化カ
ルシウム富有スラツジに対して特別な利用が可能
である場合に行なわれる。 The sludge removed from the first and second neutralization steps at 4 and 7 can be fed together to a common mechanical dewatering step 10, where it is dewatered to a residual water content of less than 70% by weight. Following this, the sludge is dried in a drying step 11, which may for example be configured as a spray dryer or a drum dryer.
The sludge is completely dried inside the tank. The dry material produced in this case is removed at 12 and can be added, for example, as a starting material for the production of hydrofluoric acid. The hot dryer exhaust gas is removed via conduit 13 and passed through heat exchanger 14
It is used to heat the treated wastewater in conduit 8. That is, it has been found that the cleaning effect in the phosphoric acid filtration step 9 can be significantly improved if the treated wastewater used as cleaning medium has a temperature of >30°C. In the flow sheet, the sludge from the first and second neutralization steps are successively processed together. However, it is of course also possible to treat the sludge separately from each other. This is done in particular if special utilization is available for the calcium fluoride-rich sludge from the first neutralization step.
通常の場合、第２中和工程６に続いて生じる処
理された廃水を完全に導管８によつてリン酸濾過
工程９に戻し、ここで洗浄水として再使用しうる
事から出発する事が出来る。しかしこれが特別の
場合に可能でない場合には処理された過剰の廃水
を導管１５によつて取り出し、蒸発濃縮工程１６
中でさらに処理することが可能である。これはた
とえば、前接されたリン酸製造装置における生産
故障の場合であるか、または高められた沈殿物量
のためセツコウスラツジ堆積所からの高められた
廃水量が生じる場合である。最後に、処理された
廃水の部分的蒸発濃縮は、閉じられた廃水循環系
中で熔解した特定の内容物質の許容できない富化
が生じるときでも、行われうる。 In the normal case, it is possible to proceed from the fact that the treated wastewater resulting from the second neutralization step 6 is completely returned via line 8 to the phosphoric acid filtration step 9, where it can be reused as wash water. . However, if this is not possible in special cases, the excess treated waste water can be removed via conduit 15 and an evaporative concentration step 16
Further processing is possible inside. This is the case, for example, in the case of a production failure in the adjacent phosphoric acid production plant, or if increased amounts of sediment result in increased amounts of waste water from the Setsuko sludge dumping site. Finally, partial evaporative concentration of the treated wastewater can be carried out even when an unacceptable enrichment of certain melted contents occurs in the closed wastewater circulation system.
蒸発濃縮工程１６中で、導管１５により取り出
される廃水の部分が留出物とかん水とに分けられ
る。実際には蒸留水である留出物は導管１７によ
つて取り出され、清水、冷却水またはボイラ用水
としてプラント内で使用することが出来る。蒸発
濃縮工程１６で生じる、不純物を濃厚な形で含有
するかん水は導管１８によつて取り出され、中和
工程からのスラツジは機械的脱水工程１０の前に
添加される。従つて本発明による方法により、セ
ツコウスラツジ堆積所から流出する廃水を排水溝
へ投棄しなければならない事が避けられる。この
場合、後処理された廃水をリン酸濾過工程９に戻
す事により同時にリン酸製造の際の清水需要は相
応に低下する。 During the evaporative concentration step 16, the portion of the waste water removed via conduit 15 is divided into distillate and brine. The distillate, which is actually distilled water, is removed via conduit 17 and can be used within the plant as fresh water, cooling water or boiler water. The brine containing impurities in concentrated form resulting from the evaporative concentration step 16 is removed via a conduit 18 and the sludge from the neutralization step is added before the mechanical dewatering step 10. The method according to the invention thus avoids having to dump the wastewater flowing out of the sludge dump into a drain. In this case, by returning the after-treated wastewater to the phosphoric acid filtration step 9, at the same time the demand for fresh water during phosphoric acid production is correspondingly reduced.
図面は本発明による方法の１実施例を示すフロ
ーシートである。
１……セツコウスラツジ堆積所、３……第１中
和工程、６……第２中和工程、９……リン酸濾過
工程、１０……脱水工程、１１……乾燥工程、１
４……熱交換器、１６……蒸発濃縮工程。
The drawing is a flow sheet illustrating one embodiment of the method according to the invention. 1...Setsukou Sludge Depository, 3...First Neutralization Step, 6...Second Neutralization Step, 9...Phosphoric Acid Filtration Step, 10...Dehydration Step, 11...Drying Step, 1
4... Heat exchanger, 16... Evaporation concentration step.
Claims (1)
製造する際に生じる廃水をカルシウムイオンを用
いて中和し、スラツジを分離しかつ洗浄水として
リン酸製造の濾過工程に戻すことにより該廃水を
処理し、その際、リン鉱石分解の際に生じるセツ
コウスラツジを液状で捨場に堆積する方法におい
て、 ａ セツコウスラツジ堆積物から流出する廃水
を、第１中和工程で2.5〜4.5のPH値にし、その
際に生じるスラツジを分離し、 ｂ その後スラツジの除去された廃水を、第２中
和工程で９〜13のPH値にし、それに引続き、第
２のスラツジを分離し、 ｃ 双方の中和工程で生じるスラツジを、個々に
または一緒に、機械的脱水後に乾燥工程でさら
に処理しかつ ｄ リン酸製造の濾過工程に戻されなかつた処理
された過剰の廃水を、蒸発濃縮工程でさらに処
理し、その際、そこで生じる留出物を清水、冷
却水またはボイラ用水として使用し、生じる塩
溶液を双方の中和工程からのスラツジと一緒に
乾燥させる ことを特徴とする、リン鉱石の硫酸での湿式分
解によりリン酸を製造する際に生じる廃水の処
理法。 ２ 廃水の中和工程の際に生じるスラツジを乾燥
工程へ導入する前に機械的脱水により70重量％よ
り少ない残存含水量にまで脱水する、特許請求の
範囲第１項記載の方法。 ３ 乾燥工程からの廃ガスを、直接または間接的
に、処理された廃水を加熱するために利用し、該
廃水を洗浄水としてリン酸製造の濾過工程に戻
す、特許請求の範囲第１項または第２項記載の方
法。 ４ 処理された＞30℃の温度を有する廃水を、リ
ン酸製造の濾過工程に供給する、特許請求の範囲
第１項から第３項までのいずれか１項記載の方
法。[Scope of Claims] 1. Waste water generated during the production of phosphoric acid by wet decomposition of phosphate rock with sulfuric acid is neutralized using calcium ions, the sludge is separated, and the sludge is used as washing water in the filtration process of phosphoric acid production. In a method in which the wastewater is treated by returning the wastewater, and at that time, the sludge produced during the decomposition of phosphate rock is deposited in a liquid state in a dumping site, a. b. The wastewater from which the sludge has been removed is then brought to a pH value of 9 to 13 in a second neutralization step, and subsequently the second sludge is separated; c. Both. The sludge resulting from the neutralization step is further treated, either individually or together, in a drying step after mechanical dewatering, and d. The excess wastewater that has not been returned to the filtration step of the phosphoric acid production is carried out in an evaporative concentration step. Further processing of phosphate rock, characterized in that the resulting distillate is used as fresh water, cooling water or boiler water, and the resulting salt solution is dried together with the sludge from both neutralization steps. A method for treating wastewater generated during the production of phosphoric acid by wet decomposition with sulfuric acid. 2. A method according to claim 1, wherein the sludge produced during the neutralization step of the wastewater is dehydrated by mechanical dewatering to a residual water content of less than 70% by weight before being introduced into the drying step. 3. The waste gas from the drying process is used, directly or indirectly, to heat treated wastewater, and the wastewater is returned as wash water to the filtration process of phosphoric acid production, or The method described in Section 2. 4. Process according to any one of claims 1 to 3, characterized in that the treated wastewater having a temperature of >30° C. is fed to a filtration step for the production of phosphoric acid.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3314248.3 | 1983-04-20 | ||
| DE19833314248 DE3314248A1 (en) | 1983-04-20 | 1983-04-20 | Process for treating the waste water produced in the production of wet phosphoric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59199095A JPS59199095A (en) | 1984-11-12 |
| JPH0453600B2 true JPH0453600B2 (en) | 1992-08-27 |
Family
ID=6196837
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59076749A Granted JPS59199095A (en) | 1983-04-20 | 1984-04-18 | Treatment of waste water generated in producing phosphoric acid by performing wet decomposition of phosphate ore with sulfuric acid |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS59199095A (en) |
| AT (1) | AT390602B (en) |
| DD (1) | DD219470A5 (en) |
| DE (1) | DE3314248A1 (en) |
| IN (1) | IN160464B (en) |
| ZA (1) | ZA841733B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT396227B (en) * | 1989-08-17 | 1993-07-26 | Perlmooser Zementwerke Ag | Neutralizing agent having depot effect |
| JP2002035766A (en) * | 2000-07-21 | 2002-02-05 | Japan Organo Co Ltd | Method for removing fluorine and phosphorus in wastewater |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1160376B (en) * | 1959-05-14 | 1963-12-27 | Knapsack Ag | Process for the treatment of waste water from phosphorus production |
| AT348947B (en) * | 1977-03-02 | 1979-03-12 | Voest Ag | PROCEDURE FOR NEUTRALIZING ACID RINSING WATERS OR USED PICKLING ACIDS FROM METAL PICKLING |
| DD146446A1 (en) * | 1979-10-04 | 1981-02-11 | Hans Hoppe | PROCESS FOR PHOSPHATE ELIMINATION FROM WASTEWATERS |
| DE2943870A1 (en) * | 1979-10-30 | 1981-06-11 | Universal Gesellschaft zur Errichtung von Umweltschutzanlagen mbH & Co, 2410 Mölln | Sewage clarification - in two flock(s) precipitation stages by injecting calcium salt and iron salt in aeration up draught |
| US4301014A (en) * | 1980-06-05 | 1981-11-17 | Hooker Chemicals & Plastics Corp. | Phosphorus pentasulfide waste water treatment |
| DE3038336A1 (en) * | 1980-10-10 | 1982-05-27 | Hoechst Ag, 6000 Frankfurt | METHOD FOR PROCESSING WASTE WATER CONTAINING PHOSPHORUS |
-
1983
- 1983-04-20 DE DE19833314248 patent/DE3314248A1/en active Granted
-
1984
- 1984-03-08 IN IN219/DEL/84A patent/IN160464B/en unknown
- 1984-03-08 ZA ZA841733A patent/ZA841733B/en unknown
- 1984-03-29 AT AT0107584A patent/AT390602B/en not_active IP Right Cessation
- 1984-04-16 DD DD84262016A patent/DD219470A5/en not_active IP Right Cessation
- 1984-04-18 JP JP59076749A patent/JPS59199095A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59199095A (en) | 1984-11-12 |
| ZA841733B (en) | 1984-10-31 |
| DD219470A5 (en) | 1985-03-06 |
| DE3314248A1 (en) | 1984-10-25 |
| DE3314248C2 (en) | 1991-06-13 |
| AT390602B (en) | 1990-06-11 |
| ATA107584A (en) | 1989-11-15 |
| IN160464B (en) | 1987-07-11 |
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