JPH0359451A - Method for measuring concentration of primary ammonium phosphate - Google Patents

Method for measuring concentration of primary ammonium phosphate

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Publication number
JPH0359451A
JPH0359451A JP19394289A JP19394289A JPH0359451A JP H0359451 A JPH0359451 A JP H0359451A JP 19394289 A JP19394289 A JP 19394289A JP 19394289 A JP19394289 A JP 19394289A JP H0359451 A JPH0359451 A JP H0359451A
Authority
JP
Japan
Prior art keywords
end point
stage
point
change
determined
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.)
Pending
Application number
JP19394289A
Other languages
Japanese (ja)
Inventor
Katsumi Hazama
狭間 勝美
Teruhisa Kato
輝久 加藤
Fuminori Munekane
史典 宗兼
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Kasei Corp
Original Assignee
Mitsubishi Kasei Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Kasei Corp filed Critical Mitsubishi Kasei Corp
Priority to JP19394289A priority Critical patent/JPH0359451A/en
Publication of JPH0359451A publication Critical patent/JPH0359451A/en
Pending legal-status Critical Current

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  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)

Abstract

PURPOSE:To attain the measurement of concn. with high accuracy by dropping a prescribed volume of H2SO4 into a liquid to be measured, determining the point where the magnitude relation from just before a change in pH changes as the end point of a 1st stage and determining the change point of the magnitude relation generated when the pH is at a specific value or above as the end point of the 1st stage at the time of the determination of the end point of the 1st stage. CONSTITUTION:The pH at the start of titration is measured and confirmation is made that the pH of the sample is within a prescribed range. Then, 0.01 ml H2SO4 is dropped and the change DELTApH in the pH at every drop is determined respectively as A1, A2-, AM' - AN+1. AM and AN are determined as the point where the magnitude relation of the pH changes when A1<A2 - AM> - <AN>AN+1 is assumed. The value of AM where the pH is PM is, thereupon, discarded if PM<PS (PS is the specific value of pH) and PM>PS when the pH at the points AM, AN are respectively designated as PM, PN. The point AN where the pH is the PN larger than the PS is determined as the end point of the 1st stage. Thus, the concn. of the primary ammonium phosphate is determined by the prescribed equation to be the basis for concn. detection.

Description

【発明の詳細な説明】 [産業上の利用分野1 本発明は、コークス炉ガスよりアンモニアを除去するた
めの)オサム法において用いる吸収液(第1リン酸アン
モニウム(NH41HzPO+)の濃度の測定方法に関
するものである。
Detailed Description of the Invention [Industrial Application Field 1] The present invention relates to a method for measuring the concentration of an absorption liquid (ammonium monophosphate (NH41HzPO+)) used in the Osamu method (for removing ammonia from coke oven gas). It is something.

[従来の技術] コークス炉ガス(COCl よりアンモニアを除去する
ための)オサム法で用いる吸収液である第1リン酸アン
モニウム(NH,1H2P04の濃度測定方法として従
来次の方法が知られている。
[Prior Art] The following method is conventionally known as a method for measuring the concentration of diammonium phosphate (NH, 1H2P04), which is an absorption liquid used in the Osamu method for removing ammonia from coke oven gas (COCl).

それは、硫酸(H2SO4)並びに水酸化ナトリウムl
Na口旧の標準液により電位差滴定により行なわれる、
即ち、まず酸量の(例えば2a+1の)試料を採取し、
一定量(例えば50o+1)の稀釈水でサンプル計量器
の洗浄も兼ねて稀釈し滴定セルへ送る。
It contains sulfuric acid (H2SO4) as well as sodium hydroxide l
Performed by potentiometric titration with Na standard solution.
That is, first take a sample with an acid amount (for example, 2a+1),
The sample is diluted with a certain amount (for example, 50°+1) of dilution water, which also serves as a wash for the sample measuring device, and sent to the titration cell.

この試料をH2SO4、NaOH標準液で滴定する。This sample is titrated with H2SO4, NaOH standard solution.

最初にHaSO,で滴定すると、H2SO4は試料中の
第ニリン酸アンモニウムと(1)に示すように反応して
当量点においてPHが急変する。
When first titrating with HaSO, H2SO4 reacts with ammonium diphosphate in the sample as shown in (1), causing a sudden change in pH at the equivalence point.

2 tst+4+ RHPOa+H2SO4→2Nl(
JtPOl” fNH−) 1sO4(t1次に上の溶
液なNaOHで滴定すると、Mail(は溶液中の第一
リン酸アンモニウム(原試料中に存在していたものと反
応(11によって生じたもの)と次の(2)に示すよう
に反応して当量点においてPHの急変が生ずる。
2 tst+4+ RHPOa+H2SO4→2Nl(
JtPOl" fNH-) 1sO4 (t1) Then, when titrated with the above solution of NaOH, Mail( reacts with the monoammonium phosphate in the solution (that which was present in the original sample (formed by 11)). As shown in the following (2), the reaction causes a sudden change in pH at the equivalence point.

N11411−PO+Na0H= N)14NallP
O++HaO(21上記のように反応させ夫々PHの変
化ΔPHを求めその変化の大きい点(終点)を求め、こ
れにより吸収液である第ニリン酸アンモニウムの濃度を
測定する。
N11411-PO+Na0H=N)14NallP
O++HaO (21) are reacted as described above, and the change in pH ΔPH is determined, the point where the change is large (end point) is determined, and the concentration of ammonium diphosphate, which is the absorption liquid, is measured.

[発明が解決しようとする課題] 第4図、第5図は、前記の滴定の際のPHの変化ΔPH
の変化量を示すもので、第4図は1段目の終点付近、第
5図は2段目の終点付近のグラフである。つまりRが1
段目の終点であり、Tが2段目の終点である。
[Problems to be Solved by the Invention] Figures 4 and 5 show the change in pH ΔPH during the above titration.
4 is a graph near the end point of the first stage, and FIG. 5 is a graph near the end point of the second stage. That is, R is 1
This is the end point of the second stage, and T is the end point of the second stage.

ここで1段目においては、例えば第4図に示ずRoのよ
うに実際の終点Rよりも前の点を終点とすることがあり
、当量点との誤差が大きすぎて正確な測定が出来ない。
Here, in the first stage, the end point may be a point before the actual end point R, such as Ro not shown in Figure 4, and the error with the equivalent point is too large to allow accurate measurement. do not have.

又2段目の場合変化が比較的ゆるやかであるためΔPH
が1デジツト以下になりΔPHが変化しなくなりNaO
Hが高いところを終点とし正確な測定が出来なくなる。
In addition, in the case of the second stage, since the change is relatively gradual, ΔPH
becomes less than 1 digit and ∆PH stops changing and NaO
The end point is a point where H is high, and accurate measurement becomes impossible.

つまり第5図においてToを終点とする。That is, in FIG. 5, To is the end point.

以上の滴定におけるPHの変化を示したグラフが第1図
である。この図においてRが1段目の急変点(終点)で
ありTが2段目の急変点(終点)である。
FIG. 1 is a graph showing the change in pH during the above titration. In this figure, R is the sudden change point (end point) of the first stage, and T is the sudden change point (end point) of the second stage.

このような滴定の結果から、次の式(3)、(41を用
いて試料中のアンモニア、リン酸の各濃度を求めること
が出来る。
From the results of such titration, the concentrations of ammonia and phosphoric acid in the sample can be determined using the following equations (3) and (41).

N114 (a+oll =  (L X A + f
aX B )/v       131HaP04(w
all=  (fxX B l/v         
  (4)ただし、Aは1段目の終点までのHaSO4
の量(moll 、 Bは1段目の終点から2段目の終
点までのNa011の量(n+11. flは+t、S
O4のファクター、f2はNaOHのファクター、■は
試料の採取量である。
N114 (a+oll = (L X A + f
aX B )/v 131HaP04(w
all= (fxX B l/v
(4) However, A is HaSO4 up to the end point of the first stage
amount (mol), B is the amount of Na011 from the end point of the first stage to the end point of the second stage (n+11. fl is +t, S
The O4 factor, f2 is the NaOH factor, and ■ is the amount of sample collected.

したがって本発明は、1段目の終点のおよび2段目の終
点の決定に当たって、いずれも正しい点を終点として定
めることが正確に行なわれ得る第1リン酸アンモニウム
の濃度測定方法を提供する6のである。
Therefore, the present invention provides a method for measuring the concentration of monoammonium phosphate that can accurately determine the correct point as the end point in determining the end point of the first stage and the end point of the second stage. be.

[課題を解決するための手段] 本発明の第一リン酸アンモニウムの濃度測定方法は、所
定量の11□304を滴下し被測定液のPIIの変化量
ΔPHを順次求め、PHの急変点であるΔPHの大小関
係が変化する点をもって1段目の終点とし、次いで所定
量のNaOHを滴下して被測定液のPSIの変化量ΔP
Hを順次求め、PHの急変点であるΔPHの大小関係の
変化する点をもって2段目の終点とし。
[Means for Solving the Problems] The method for measuring the concentration of monoammonium phosphate of the present invention involves dropping a predetermined amount of 11□304, sequentially determining the amount of change ΔPH in PII of the liquid to be measured, and detecting the change at the point of sudden change in pH. The point at which the magnitude relationship of a certain ΔPH changes is defined as the end point of the first stage, and then a predetermined amount of NaOH is dropped to determine the amount of change ΔP in PSI of the liquid to be measured.
H is determined sequentially, and the point at which the magnitude relationship of ΔPH changes, which is a sudden change in PH, is set as the end point of the second stage.

これら1段目の終点および2段目の終点での液量にもと
づいて第一リン酸アンモニウムの濃度を測定するもので
、1段目の終点決定にあたって所定のPH値以上のとこ
ろでのΔPHの大小関係が変化した点を1段目の終点と
するちのである。これによって第2図に示すように所定
PHのPsの点よりtPHが大である領域での急変点R
を終点として定めることが出来る。これによって、従来
の方法のようにRoを終点とすることを避けることが出
来る。
The concentration of monoammonium phosphate is measured based on the liquid volume at the end point of the first stage and the end point of the second stage, and the magnitude of ΔPH at a predetermined pH value or higher is used to determine the end point of the first stage. The point where the relationship changes is set as the end point of the first stage. As a result, as shown in FIG.
can be set as the end point. This makes it possible to avoid setting Ro as the end point as in the conventional method.

又2段目の終点の決定にあたっては、ΔPHの大小関係
の変化が、第3図に示すような場合、その変化開始点T
1と変化終了点T2を求め5それらの中間点Tを終点と
するものである。
In addition, when determining the end point of the second stage, if the change in the magnitude relationship of ΔPH is as shown in Figure 3, the change starting point T
1 and the change end point T2 are found, and the intermediate point T between them is set as the end point.

したがって、従来の方法のように第5図に示すToを終
点とすることはなく、適切な終点の決定が可能である。
Therefore, unlike the conventional method, To shown in FIG. 5 is not set as the end point, and an appropriate end point can be determined.

[実施例] +11初期PHの検出 滴定開始時のPHを測定し、試料が所定範囲内のPHで
あることを確認する。
[Example] +11 Detection of initial pH The pH at the start of titration is measured and it is confirmed that the pH of the sample is within a predetermined range.

(2)1段目の終点検出 0、 Ola+lのH,S04を滴下し、その都度のl
)Hの変化量をΔPHを夫々A、、A、+、A、、・・
・、 A1.l−1,A&ll Av++A、、、A、
、A□1とする。
(2) First stage end point detection 0, Ola+l H, S04 is dropped, and each time
)H change amount and ΔPH are respectively A,, A, +, A,...
・, A1. l-1,A&ll Av++A,,,A,
, A□1.

ここでAI<A、<A、<・・・All −+ < A
ll > A、や、・・・AM−1<As>A、14+
であったとするとA4とAsがΔPHが大小関係が変化
する点として求められる。
Here, AI<A, <A, <...All −+ <A
ll > A, Ya...AM-1<As>A, 14+
If this is the case, A4 and As can be found as points at which the magnitude relationship of ΔPH changes.

ここでAM、 AMの点でのPHを夫々p、、 p、と
する時、九<Pi、 PN>P、であれば、PHがPv
であるA2の点は終点とせず捨てる。そしてPHがP3
よりの大の1’Nの点Anを1段目の終点とする。
Here, when the PH at the points AM and AM are p, , p, respectively, if 9<Pi, PN>P, then PH is Pv
Point A2, which is , is not considered as the end point and is discarded. And the PH is P3
Let the point An of 1'N with the larger value be the end point of the first stage.

これをグラフで示したのが第2図である6つまりこの図
においてグラフ中ピークがA、とAnの二つあるが、そ
のうちのP、よりも大きいPHのA、の点が1段目の終
点である。
This is shown in a graph in Figure 2.6 In other words, in this figure, there are two peaks in the graph, A and An, and the point A, which has a larger PH than P, is in the first row. It is the end point.

これに対して従来の方法においては第4図に示すように
グラフの最初のピークAM(T’lを終点としてしまう
、そしてこの時の液量をもとにリン酸アンモニウムの濃
度を求めることになり誤まった値となる。
On the other hand, in the conventional method, the end point is the first peak AM (T'l) of the graph as shown in Figure 4, and the concentration of ammonium phosphate is determined based on the liquid volume at this time. This will result in an incorrect value.

(3)2段目の終点の検出 1段目と同様に0.01m1のNaOHを滴下し、その
時のPHの変化量ΔPHをり、Bg、・・・+BN−1
+BN+BNとする。
(3) Detection of the end point of the second stage Drop 0.01 ml of NaOH in the same way as the first stage, and calculate the amount of change in PH at that time ΔPH, Bg,...+BN-1
+BN+BN.

ここで Bl<8.<−<8N−1< Bs> Bnl
となった場合は、ΔPHがBNの時の液量を終点の液量
とする。
Here Bl<8. <-<8N-1<Bs> Bnl
In this case, the liquid volume when ΔPH is BN is set as the liquid volume at the end point.

又B+ < Bz< ・= < B+a= Bu−t 
= −= BN−1< Bn< BN+1となった場合
は、ΔPHがB、の時の液量MとΔPHがBNの時の液
量Nから(M+Nl/2を終点の液量とする。
Also, B+ <Bz< ・= < B+a= But-t
= -= BN-1 < Bn < BN+1, from the liquid volume M when ΔPH is B and the liquid volume N when ΔPH is BN, (M+Nl/2 is taken as the liquid volume at the end point.

このように本実施例においては、2段目の終点として第
3図のTを検出しその時の液量に相当する(M+Nl 
/2を液量としている。
In this example, T in FIG. 3 is detected as the end point of the second stage, and corresponds to the liquid volume at that time (M+Nl
/2 is the liquid volume.

これに対し従来の方法では、第5図のT゛を終点とする
ことになる。
In contrast, in the conventional method, T'' in FIG. 5 is the end point.

以上のようにして求めた1段目の終点と2段目の終点の
液量にもとづいて、既に述べた濃度検出のための基礎と
なる+31141式により第1リン酸アンモニウムの濃
度が決定される。
Based on the liquid volumes at the end point of the first stage and the end point of the second stage determined as described above, the concentration of monoammonium phosphate is determined by the +31141 formula, which is the basis for concentration detection described above. .

[発明の効果] 以上述べたように、本発明の方法によれば、1段目の終
点の決定に際して試料のPHが所定の値以上の範囲内に
おいて定めることにしたので、他の要因によるPHの急
変点を終点とすることむしに正しい終点を求めることが
出来る。又2段目の終点の決定に際しては、変化の開始
と変化の終了の中間点を終点を定めることによって正し
い終点を求めることが出来る。これによって従来方法よ
りも精度の高い濃度測定が可能になる。
[Effects of the Invention] As described above, according to the method of the present invention, when determining the end point of the first stage, it is determined that the pH of the sample is within a range of a predetermined value or higher, so that the pH due to other factors is not affected. It is possible to find the correct end point by taking the abrupt turning point as the end point. When determining the end point of the second stage, the correct end point can be determined by determining the end point as the midpoint between the start of the change and the end of the change. This makes it possible to measure concentration with higher accuracy than conventional methods.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は本発明の方法の基本原理による測定時のPHの
変化を示したグラフ、第2図は本発明の方法による1段
目の終点の決定手段を示した図、第3図は本発明の方法
による2段目の終点の決定手段を示した図、第4図、第
5図は夫々従来方法の1段目、2段目における終点決定
手段を示す図である。
FIG. 1 is a graph showing the change in pH during measurement according to the basic principle of the method of the present invention, FIG. 2 is a graph showing the means for determining the end point of the first stage according to the method of the present invention, and FIG. FIGS. 4 and 5 are diagrams showing end point determining means in the second stage according to the method of the invention, and FIGS. 4 and 5 are diagrams showing end point determining means in the first stage and second stage, respectively, of the conventional method.

Claims (2)

【特許請求の範囲】[Claims] (1)被測定液に所定量のH_2SO_4を滴下しその
PHの変化量を順次求め変化量の直前のものとの大小関
係が変化する点を1段目の終点とし、次いで所定量のN
aOHを滴下してPHの変化量を順次求め変化量の直前
のものとの大小関係が変化する点を2段目の終点とし、
1段目の終点における液量と2段目の終点における液量
とから第1リン酸アンモニウムの濃度を測定する方法に
おいて、1段目の終点の決定の際にPHが特定の値以上
の時に生じた前記大小関係の変化点をもって1段目の終
点とすることを特徴とした濃度測定方法。
(1) Drop a predetermined amount of H_2SO_4 into the liquid to be measured, sequentially calculate the amount of change in PH, set the point where the magnitude relationship with the previous one changes as the end point of the first stage, then add a predetermined amount of N
The amount of change in PH is sequentially determined by dropping aOH, and the point where the magnitude relationship with the previous amount of change changes is set as the end point of the second stage,
In the method of measuring the concentration of monoammonium phosphate from the liquid volume at the end point of the first stage and the liquid volume at the end point of the second stage, when the pH is above a specific value when determining the end point of the first stage. A concentration measuring method characterized in that the point of change in the magnitude relationship that occurs is taken as the end point of the first stage.
(2)被測定液に所定量のH_2SO_4を滴下しその
PHの変化量を順次求め変化量の直前のものとの大小関
係が変化する点を1段目の終点とし、次いで所定量のN
aOHを滴下してPHの変化量を順次求め変化量の直前
のものとの大小関係が変化する点を2段目の終点とし、
1段目の終点における液量と2段目の終点における液量
とから第1リン酸アンモニウムの濃度を測定する方法に
おいて、2段目の終点の決定の際に前記大小関係の変化
の開始点の液量と終了点の液量との平均液量をもって2
段目の終点の液量とすることを特徴とする濃度測定方法
(2) Drop a predetermined amount of H_2SO_4 into the liquid to be measured, sequentially calculate the amount of change in PH, set the point at which the magnitude relationship with the one immediately before the change changes as the end point of the first stage, then add a predetermined amount of N
The amount of change in PH is sequentially determined by dropping aOH, and the point where the magnitude relationship with the previous amount of change changes is set as the end point of the second stage,
In the method of measuring the concentration of monoammonium phosphate from the liquid volume at the end point of the first stage and the liquid volume at the end point of the second stage, when determining the end point of the second stage, the starting point of the change in the magnitude relationship is determined. The average liquid volume between the liquid volume at the end point and the liquid volume at the end point is 2.
A concentration measuring method characterized by measuring the liquid volume at the end point of each stage.
JP19394289A 1989-07-28 1989-07-28 Method for measuring concentration of primary ammonium phosphate Pending JPH0359451A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP19394289A JPH0359451A (en) 1989-07-28 1989-07-28 Method for measuring concentration of primary ammonium phosphate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP19394289A JPH0359451A (en) 1989-07-28 1989-07-28 Method for measuring concentration of primary ammonium phosphate

Publications (1)

Publication Number Publication Date
JPH0359451A true JPH0359451A (en) 1991-03-14

Family

ID=16316311

Family Applications (1)

Application Number Title Priority Date Filing Date
JP19394289A Pending JPH0359451A (en) 1989-07-28 1989-07-28 Method for measuring concentration of primary ammonium phosphate

Country Status (1)

Country Link
JP (1) JPH0359451A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9655435B2 (en) 2008-12-15 2017-05-23 Glaxosmithkline Consumer Healthcare Gmbh & Co., Kg Toothbrush bristle arrangement

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9655435B2 (en) 2008-12-15 2017-05-23 Glaxosmithkline Consumer Healthcare Gmbh & Co., Kg Toothbrush bristle arrangement

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