Explain the problems and solutions encountered in the production of phosphating solution
Product introduction
It is widely used in large air separation and sheet making equipment, and the application field covers the high-end aspects such as the storage and transportation of crude oil in yibi ships.
Project parameters
The diameter of:1.0-1.3 1.3-1.5
The adsorption time of test condition was 58s with an average pressure of 1-2s
Adsorption pressure
Nitrogen purity (%)
Yield (Nm3/ h.t.)
Nitrogen recovery rate
0.8MPa
99.99
95
24
99.9
160
29
99.5
240
35
99
320
42
98
400
43
97
490
48
96
560
51
95
620
55
0.6MPa
99.99
75
27
99.9
130
30
99.5
190
37
99
260
42
98
320
44
97
390
50
96
445
52
95
500
56
Explain the problems and solutions encountered in the production of phosphating solution
Common phosphating quality problems and solutions
Number phenomenon causes the appearance of quality problems  Solution Â
1 non-phosphorus film or phosphate film is not easy to form  The workpiece is entirely or partially non-phosphorized, sometimes blue or blank Â
(1) The surface of the workpiece has a hardened layer;
(2) The total acidity is insufficient;
(3) Low processing temperature
(4) The free acid is too low
(5) Degreasing is not clean or the phosphating time is short; (6) Hydrogen is accumulated on the surface of the workpiece;
(7) The proportion of the phosphating bath is out of balance, such as the P2O5 content is too low;
(8) Workpiece overlap or contact between workpieces
(1) Improve the processing method or remove the hardened layer by pickling and sand blasting to meet the surface treatment requirements;
(2) Supplemental phosphating agent:
(3) raising the temperature of the phosphating bath;
(4) supplemental phosphating agent;
(5) Strengthen degreasing or prolong phosphating time;
(6) flipping the workpiece or changing the position of the workpiece;
(7) adjusting or replacing the phosphating bath;
(8) Pay attention to increase the workpiece gap and avoid contact
Number phenomenon causes the appearance of quality problems  Solution Â
2 Phosphating film too thin Phosphating film is too thin, crystallized too fine or no obvious crystallization, poor corrosion resistance.
(1) The total acidity is too high;
(2) Phosphating time is not enough
(3) The processing temperature is too low
(4) The concentration of the accelerator is high;
(5) The surface of the workpiece has a hardened layer
(6) low ferrous ion content;
(7) Poor surface adjustment effect or surface adjustment failure
(1) adding water to dilute the phosphating bath;
(2) prolonging the phosphating time;
(3) raising the processing temperature;
(4) stop adding the accelerator;
(5) Cleaning with acid or sandblasting to meet surface treatment requirements;
(6) Inserting an iron plate and detecting changes in total acidity or free acidity;
(7) replacing or adding a surface conditioner;
Number phenomenon causes the appearance of quality problems  Solution Â
3 phosphating film crystals coarse phosphating film crystal coarse, loose, porous, surface rust
(1) The workpiece is not cleaned;
(2) The workpiece is rusted before phosphating;
(3) The ferrous ion content is low;
(4) The free acid base is low;
(5) low phosphating temperature;
(6) The surface of the workpiece is over-etched;
(1) Surface pretreatment of the workpiece before strong phosphating;
(2) reducing the exposure time of the workpiece in the air after rust washing;
(3) increasing the content of ferrous ions, such as adding iron dihydrogen phosphate;
(4) adding phosphoric acid or the like to increase free acidity;
(5) increase the humidity of the bath;
(6) Control the rust removal time or replace the rust remover;
Number phenomenon causes the appearance of quality problems  Solution Â
4 Phosphating film ash phosphating film has white powder after drying
(1) The slag content of the bath is too large
(2) the acid ratio is too high;
(3) The treatment temperature is too high;
(4) The sediment at the bottom of the tank floats and sticks to the workpiece.
(5) The surface oxide of the workpiece is not removed;
(6) The oxidant content of the solution is too high and the total acidity is too high.
(1) Remove the bottom residue and filter regularly
(2) Supplemental phosphating agent
(3) Reduce the humidity of phosphating
(4) Allow the phosphating bath to stand still and turn the groove
(5) Strengthen pickling and wash thoroughly
(6) Stop adding oxidant and adjust the ratio of acid
Number phenomenon causes the appearance of quality problems  Solution Â
5 Phosphating film hair phosphating film is uneven, with obvious sag marks
(1) Degreasing is not clean
(2) The surface conditioner is not effective or has failed
(3) Phosphating bath spray uneven
(4) Work surface passivation
(5) Low phosphating temperature
(1) Strong degreasing or replacement of degreasing agent
(2) Replace or supplement the table regulator
(3) Check and adjust the nozzle
(4) Strengthen pickling or sand blasting
(5) increase the phosphating temperature
Number phenomenon causes the appearance of quality problems  Solution Â
6 The phosphating film is black and partially black, and the film is black and rough.
(1) The accelerator concentration is too low
(2) Excessive pickling
(1) Adding accelerator
(2) Control pickling time
Number phenomenon causes the appearance of quality problems  Solution Â
7 Phosphating surface rust and phosphating, yellow rust or rust spots on the surface of the workpiece
(1) The phosphating film grains are too thick or too fine to reduce the corrosion resistance
(2) The free acid content is too high
(3) Over-etching of workpiece surface
(4) Insufficient phosphate content in solution
(5) Residual acid on the surface of the workpiece
(6) There are many precipitates in the phosphating tank, and the nozzle has been blocked.
(7) Low processing temperature
(8) Equipment reasons, such as excessive pressure of the spray, nozzle direction, etc.
(1) Adjust the ratio of free acidity to total acidity
(2) reduce the free acid content, can add zinc oxide or zinc hydroxide
(3) Control the pickling process
(4) Supplementation of trihydrogen phosphate
(5) Strengthening neutralization and washing
(6) Check the nozzle and clean it to check the amount of precipitation in the phosphating tank
(7) Improve processing humidity
(8) Check whether the device is running normally one by one.
Number phenomenon causes the appearance of quality problems  Solution Â
8 phosphating film red phosphating film red but not rust (1) copper ions infiltrating phosphating solution
(2) Iron slag adhesion in pickling solution
(1) Pay attention to the use of copper hangers; replace with iron scraps or use vulcanization to adjust acidity
(2) Strengthen the quality control of the pickling process
Number phenomenon causes the appearance of quality problems  Solution Â
9 film is a rainbow spotted with a nail through the scratches, looking at the rainbow color
(1) The accelerator concentration is too high
(2) Uneven distribution of accelerators
(3) Degreasing is not thorough
(1) Stopping accelerator
(2) Stir well to make it uniform
(3) supplemental degreaser
Number phenomenon causes the appearance of quality problems  Solution Â
10 phosphating bath liquid black phosphating bath liquid becomes black turbid
(1) The bath temperature is lower than the specified temperature
(2) Excessive ferrous ion in solution
(3) Total acidity is too low
(1) Stop phosphating, increase the temperature of the bath to the boiling point, keep it for 1 to 2 hours , and stir with air until the primary color is restored.
(2) oxidants, such as potassium permanganate, etc.
(3) Supplement zinc nitrate to increase total acidity
Number phenomenon causes the appearance of quality problems  Solution Â
11 phosphating film blue phosphating film part of the surface produces purple blue color Â
(1) The pH of the surface conditioner is not in the process range
(2) Water mist nozzle blockage in the surface of the phosphating zone
(3) The zinc ion content of the phosphating bath is insufficient
(4) The amount of accelerator in the phosphating bath is not enough
(1) supplemented with real table transfers or added Na2CO3, to increase the PH value
(2) Checking and cleaning the water mist nozzle
(3) Supplemental phosphating solution or zinc nitrate
(4) Supplementary accelerator
Number phenomenon causes the appearance of quality problems  Solution Â
12 film blistering , the coating film blistering
(1) Insufficient water washing after phosphating
(2) The cleaning water is polluted
(3) The quality of pure water is not good
(4) dripping water on hangers or conveyor belts
(1) Inspection nozzle and washing method
(2) increasing the amount of water, controlling the conductivity of the washing water in 150 μ S / cmc less
(3) controlling the conductivity of pure water at 5 μ S / cm or less
(4) Eliminate such dripping
[This article is edited and edited by Xianghe Phosphate Division. If you need to reprint, please indicate in the form of link: Phosphate Hefei Xianghe Phosphate Coating Co., Ltd. http:// ,Thank you]
HHCMS-240 type Carbon Molecular Sieve
HHCMS-240 is a new kind of non-polar adsorbent. It is designed to extract nitrogen-rich gas from the air. It is suitable for separating nitrogen from the air.
The most notable features of the carbon molecular sieve are high gas-producing efficiency and low waste, especially nitrogen with a purity higher than 99.9%.
Packing density:≥680-700kg/m³
The intensity of particle:≥95
Compressive strength abrasion:≤1%
The moisture content:≤0.5%
Standard packing:20Kg/barrel. 40Kg/barrel. 130Kg/barrel
Pay attention to
1. The nitrogen production equipment can reduce the adsorption temperature to better show its excellent nitrogen production performance under conditions;
2. Pay attention to low temperature drying and seal preservation during storage;
Molecular Sieves Hhcms-240,Molecular Sieves For Drying Solvents,Molecular Sieve Regeneration Process,Carbon Molecular Sieves Types
Zhejiang Changxing Haihua Chemical Co.,Ltd. , http://www.zjcxhhcms.com