CN103143551A - Original form dechroming method for chrome leather fragment, and application of product thereof in fertilizer aspect - Google Patents
Original form dechroming method for chrome leather fragment, and application of product thereof in fertilizer aspect Download PDFInfo
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- CN103143551A CN103143551A CN2013101022982A CN201310102298A CN103143551A CN 103143551 A CN103143551 A CN 103143551A CN 2013101022982 A CN2013101022982 A CN 2013101022982A CN 201310102298 A CN201310102298 A CN 201310102298A CN 103143551 A CN103143551 A CN 103143551A
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Abstract
The invention relates to an original form dechroming method for chrome leather fragment, and application of a product thereof in fertilizer aspect. The method comprises the following steps of: adding water and calcium oxide, soaking at 20-40 DEG C for 1-4 days, washing by water and filtering; adding water, acid and salt into the filter residue, dechroming at 20-30 DEG C for 2-4 hours, washing by water and filtering; continuing to add water, salt and alkaline into the filter residue, keeping the temperature and dechroming for 30-60 min, regulating the pH to be neutral, washing by water and filtering; obtaining an original form dechromed product of chrome leather fragment; mixing and crushing the original form dechromed product of chrome leather fragment with plant ash, pelleting, and thus containing an agricultural composite fertilizer. The composite fertilizer not only has low chrome content and is rich of potassium element and organic nitrogen, but also has certain slow release function, and can effectively promote growth of plants.
Description
Technical field
The present invention relates to the former form of chrome shavinge and take off method and the application of product aspect production fertilizer thereof of chromium.
Background technology
After the fast development of having experienced 30 years leather industries, China has become universally acknowledged leather big country, leather industry is also after paper industry and brewery industry simultaneously, become the third-largest pollution industry, approximately 8000~12,000 ten thousand tons of annual discharging tanning sewages, generation contains 30~400,000 tons of chromium scurf skin slags, and wherein main form with chrome shavinge exists, therefore, how to recycle effectively and rationally shavings and become the focus that industry is paid close attention to.
Along with the fast development of China's agricultural, the kind of agricultural fertilizer is also more and more diversified.From regulating the angle of edaphon and promotion agricultural sustainable development, fertilizer is still the focus of fertilizer product development and application.The exploitation of fertilizer is when guaranteeing sufficient nutritional labeling, and reducing costs is also very actual problem.
Zhang Peng etc. (referring to: a kind of method [P] of utilizing leather castoff Preparation of amino acid, small molecular peptide composite organic fertilizer and chromium to regain. China: CN201010556326.4. 2011.8.17.) will be hydrolyzed into protein and peptide and amino acid through the tanning waste that takes off the chromium processing, then obtain fertilizer by concentrate drying.But this technique is not analyzed chromium content in hydrolysate, and those skilled in the art do not know its application security.Simultaneously, the hydrolysate that obtains is liquid, and drying process is complicated, and granulation is restricted, and the production application cost is higher, is not suitable for applying.
In chrome shavinge, abundant nitrogen can become effective nutritional labeling of fertilizer, if can seek a kind of method with low cost, chrome shavinge is taken off chromium, and take off and do not cause after chromium chrome shavinge that a large amount of hydrolysis occur, so will be to chrome shavinge the research and development of the recycling in fertilizer and novel organic fertilizer all have great importance.
Summary of the invention
The present invention aims to provide method and the application of product aspect production fertilizer thereof that the former form of a kind of chrome shavinge is taken off chromium, by the suitable technological parameter of processing step screening reasonable in design, takes off to solve present chrome shavinge the problems that are hydrolyzed in a large number after chromium.
The present invention is by the following technical solutions:
The method that the former form of chrome shavinge is taken off chromium is characterized in that, the following step carries out:
1) raw material of the following weight proportion of weighing: 1 part of chrome shavinge, 5~10 parts, water, 0.1~0.2 part, calcium oxide, soaked 1~4 day under 20~40 ℃ of conditions, then washing filtering, get filter residue one time;
2) add 4~7 weight parts waters, 0.8~1 weight portion acid and 0.1~0.2 weight portion sodium chloride in a described filter residue, constant temperature takes off chromium 2~4h under 20~30 ℃ of conditions, and then washing filtering, get the secondary filter residue;
3) add alkali, 0.1~0.2 weight portion sodium chloride of 5~10 weight parts waters, 0.1~0.2 weight portion in the described secondary filter residue, chromium 30~60min is taken off in insulation under 20~30 ℃ of conditions, then regulates pH to neutral, and washing filtering gets filter residue three times; Take off the chromium product with obtaining the former form of chrome shavinge after described three filter residues oven dry.
Described acid refer to sulfuric acid and oxalic acid according to quality than sulfuric acid: the mixed acid that oxalic acid 1:2 ~ 4 mix; Described alkali is any one in NaOH, magnesia.
Two step seasonings are adopted in described three filter residues oven dry; At first low temperature drying 3~5h under 60~70 ℃ of conditions, reach below 20% moisture; Carry out again afterwards high temperature drying, control 110~120 ℃ of temperature, dry 40~70min.
The former form of described chrome shavinge is taken off the application of method gained end-product aspect production fertilizer of chromium, it is characterized in that, the former form of described chrome shavinge is taken off the chromium product to be ground into Powdered, ratio according to weight ratio 7:7~3 is mixed with plant ash, then press the granulation of 8mm particle size, namely get described fertilizer;
At the beginning of described crushing process divides, pulverizing and broken two steps of fine powder carry out, that is: the first step, take off the chromium product with the former form of described chrome shavinge and be ground into the coarse granule that granularity is 6 ~ 8mm; Second step further is ground into described coarse granule Powdered.
Beneficial effect of the present invention is:
(1) the present invention selects the cheap chemicals such as acid, alkali, salt for taking off Cr materials, can reduce production costs, and is conducive to the marketing of product.
(2) the shavings chromium content that takes off after chromium is low, after testing, satisfies in the fertilizer national standard requirement to chromium content≤150ppm.
(3) take off in the chromium process shavings percent hydrolysis low, the attitude that substantially holds its shape is convenient to drying and the granulation operation of product.Former form of while is taken off chromium and has been kept the part collagen fiber structure in the shavings, makes fertilizer product have certain slow-release function.
The specific embodiment
In order to understand better and to implement the present invention, further illustrate the present invention below in conjunction with specific embodiment.
Embodiment 1
Weighing chrome shavinge 50g, calcium oxide 5g, distilled water 500mL, after fully stirring, 30 ℃ of heat-insulation soaking 2d, during need often to stir to guarantee that chrome shavinge fully disperses; Washing filtering adds distilled water 350mL, 5g sodium chloride, oxalic acid 10g and concentrated sulfuric acid 15mL in filter residue, fully stir, and chromium 2h, washing filtering are taken off in 25 ℃ of insulations; Continuation adds 350mL distilled water, 5g sodium hydroxide alkali and 8g sodium chloride in filter residue, after under 25 ℃ of conditions, chromium 40min is taken off in insulation, regulate pH to neutral, and fully washing is filtered; Take off the chromium product with obtaining the former form of chrome shavinge after the filter residue oven dry.
Drying course adopts two step seasonings: low temperature drying 3h under 60~70 ℃ of conditions at first reaches below 20% moisture; Carry out again afterwards high temperature drying, control 110~120 ℃ of temperature, dry 70min.
After taking the former form of chrome shavinge and taking off chromium product 70g and pulverize, add plant ash 70g, fully mix, then press the granulation of 8mm particle size, namely get described fertilizer; At the beginning of described crushing process divides, pulverizing and broken two steps of fine powder carry out, that is: the first step, take off the chromium product with the former form of described chrome shavinge and be ground into the coarse granule that granularity is 6 ~ 8mm; Second step further is ground into described coarse granule Powdered.
Embodiment 2
Weighing chrome shavinge 50g, calcium oxide 7g, distilled water 250mL, after fully stirring, 40 ℃ of heat-insulation soaking 1d, during need often to stir to guarantee that chrome shavinge fully disperses; Washing filtering adds distilled water 300mL, 6g sodium chloride, oxalic acid 15g and concentrated sulfuric acid 15mL in filter residue, fully stir, and chromium 3h, washing filtering are taken off in 30 ℃ of insulations; Continuation adds 250mL distilled water, 7g NaOH and 5g sodium chloride in filter residue, after under 20 ℃ of conditions, chromium 30min is taken off in insulation, regulate pH to neutral, and fully washing is filtered; Take off the chromium product with obtaining the former form of chrome shavinge after the filter residue oven dry.
Drying course adopts two step seasonings: low temperature drying 4h under 60~70 ℃ of conditions at first reaches below 20% moisture; Carry out again afterwards high temperature drying, control 110~120 ℃ of temperature, dry 60min.
After taking the former form of chrome shavinge and taking off chromium product 70g and pulverize, add plant ash 30g, fully mix, then press the granulation of 8mm particle size, namely get described fertilizer; At the beginning of described crushing process divides, pulverizing and broken two steps of fine powder carry out, that is: the first step, take off the chromium product with the former form of described chrome shavinge and be ground into the coarse granule that granularity is 6 ~ 8mm; Second step further is ground into described coarse granule Powdered.
Embodiment 3
Weighing chrome shavinge 50g, calcium oxide 10g, distilled water 400mL, after fully stirring, 20 ℃ of heat-insulation soaking 4d, during need often to stir to guarantee that chrome shavinge fully disperses; Washing filtering adds distilled water 200mL, 10g sodium chloride, oxalic acid 10g and concentrated sulfuric acid 20mL in filter residue, fully stir, and chromium 4h, washing filtering are taken off in 20 ℃ of insulations; Continuation adds 500mL distilled water, 10g magnesia and 10g sodium chloride in filter residue, after under 60 ℃ of conditions, chromium 60min is taken off in insulation, regulate pH to neutral, and fully washing is filtered; Take off the chromium product with obtaining the former form of chrome shavinge after the filter residue oven dry.
Drying course adopts two step seasonings: low temperature drying 5h under 60~70 ℃ of conditions at first reaches below 20% moisture; Carry out again afterwards high temperature drying, control 110~120 ℃ of temperature, dry 40min.
After taking the former form of chrome shavinge and taking off chromium product 70g and pulverize, add plant ash 50g, fully mix, then press the granulation of 8mm particle size, namely get described fertilizer; At the beginning of described crushing process divides, pulverizing and broken two steps of fine powder carry out, that is: the first step, take off the chromium product with the former form of described chrome shavinge and be ground into the coarse granule that granularity is 6 ~ 8mm; Second step further is ground into described coarse granule Powdered.
Further illustrate beneficial effect of the present invention below by the related experiment data:
The hydrolysis situation of chrome shavinge is with percent hydrolysis, nitrogen recovery and take off the measurement of chromium rate, result such as table 1.
The former form of table 1 chrome shavinge is taken off chromium statistical effect table
Experimental group | Embodiment 1 | Embodiment 2 | Embodiment 3 |
Percent hydrolysis/% | 10.4 | 16.7 | 18.4 |
Nitrogen yield/% | 88.2 | 80.6 | 74.2 |
Take off chromium rate/% | 94.2 | 97.6 | 98.4 |
In table 1, the computing formula of percent hydrolysis is:
In formula, M
Sample---the initial mass of hydrolysis substrate, g;
m
Filter residue---the quality after the oven dry of hydrolysate suction filtration filter residue, g.
The computing formula of nitrogen yield is:
Wherein, the mensuration of nitrogen content is measured according to QB/T2722-2005.
The formula that takes off the chromium rate is:
Wherein, the mensuration of chromium content operates according to QB/T2720-2005.
As shown in Table 1, use former form dechromium method reach higher take off the chromium rate in, the shavings form is not affected substantially, nitrogen nutrition loss is less.
The prepared fertilizer of this experiment is used for the fertilising of soybean planting process, weighs the performance of organic fertilizer product by indexs such as nitrogen content, potassium content, chromium content and slowly-releasing cycles (lixiviate in 25 ℃ of hydrostatic of nitrogen element begins to reaching for 80% required time of nutrients accumulation release rate).Take plant ash as the blank group.The result statistics is as table 2.
Table 2 fertilizer performance indications
Experimental group | The blank group | Embodiment 1 | Embodiment 2 | Embodiment 3 |
Nitrogen content/% | 1.4 | 8.1 | 9.0 | 8.7 |
Potassium (K 2O) content/% | 7.3 | 3.5 | 3.0 | 3.2 |
Phosphorus (P 2O 3) content/% | 2.6 | 1.6 | 1.7 | 2.0 |
Chromium (Cr 2O 3) content/ppm | 10 | 121 | 124 | 143 |
Slowly-releasing cycle/moon | 1.4 | 7.8 | 9.4 | 8.5 |
In table 2, nitrogen content is measured according to QB/T2722-2005, and chromium content is measured according to QB/T2720-2005, and potassium content, phosphorus content and slowly-releasing cycle are measured according to NY525-2012.The indexs such as the nitrogen content of this fertilizer, potassium content, phosphorus content and chromium content satisfy in NY525-2012 requirement of fertilizer nutriment, simultaneously, compare as seen with blank, and this fertilizer has certain slow-release function.
Claims (4)
1. the former form of the chrome shavinge method of taking off chromium, is characterized in that, the following step carries out:
1) raw material of the following weight proportion of weighing: 1 part of chrome shavinge, 5~10 parts, water, 0.1~0.2 part, calcium oxide, soaked 1~4 day under 20~40 ℃ of conditions, then washing filtering, get filter residue one time;
2) add 4~7 weight parts waters, 0.8~1 weight portion acid and 0.1~0.2 weight portion sodium chloride in a described filter residue, constant temperature takes off chromium 2~4h under 20~30 ℃ of conditions, and then washing filtering, get the secondary filter residue;
3) add alkali, 0.1~0.2 weight portion sodium chloride of 5~10 weight parts waters, 0.1~0.2 weight portion in the described secondary filter residue, chromium 30~60min is taken off in insulation under 20~30 ℃ of conditions, then regulates pH to neutral, and washing filtering gets filter residue three times; Take off the chromium product with obtaining the former form of chrome shavinge after described three filter residues oven dry.
2. the former form of the chrome shavinge as claimed in claim 1 method of taking off chromium, is characterized in that, described acid refer to sulfuric acid and oxalic acid according to quality than sulfuric acid: the mixed acid that oxalic acid 1:2 ~ 4 mix; Described alkali is any one in NaOH, magnesia.
3. the former form of the chrome shavinge as claimed in claim 1 method of taking off chromium, is characterized in that, two step seasonings are adopted in described three filter residues oven dry; At first low temperature drying 3~5h under 60~70 ℃ of conditions, reach below 20% moisture; Carry out again afterwards high temperature drying, control 110~120 ℃ of temperature, dry 40~70min.
4. take off the method gained end-product of chromium in the application aspect production fertilizer according to the former form of chrome shavinge claimed in claim 1, it is characterized in that, the former form of described chrome shavinge is taken off the chromium product to be ground into Powdered, ratio according to weight ratio 7:7~3 is mixed with plant ash, then press the granulation of 8mm particle size, namely get described fertilizer;
At the beginning of described crushing process divides, pulverizing and broken two steps of fine powder carry out, that is: the first step, take off the chromium product with the former form of described chrome shavinge and be ground into the coarse granule that granularity is 6 ~ 8mm; Second step further is ground into described coarse granule Powdered.
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Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103525574A (en) * | 2013-10-24 | 2014-01-22 | 山东全杰皮革研究所有限公司 | Method for preparing washing surfactant by utilizing tanning waste chrome shavings |
CN108409452A (en) * | 2018-05-18 | 2018-08-17 | 段宝荣 | The preparation method of leaf fertilizer raw material is prepared with process hides chrome leather scrap |
CN108570105A (en) * | 2018-04-24 | 2018-09-25 | 陕西科技大学 | Acid system takes off method and the application of chromium extraction collagen |
CN109052877A (en) * | 2018-08-02 | 2018-12-21 | 广州桑尼环保科技有限公司 | A kind of chromium mud resource reclaim and the method and system of waste residue harmless treatment |
CN112759454A (en) * | 2018-06-01 | 2021-05-07 | 烟台大学 | Preparation method for preparing amino acid liquid surface fertilizer raw material from tanning chromium-containing leather scraps |
CN113061062A (en) * | 2021-03-22 | 2021-07-02 | 四川大学 | Method for preparing short peptide-growth-promoting bacterium compound fertilizer by dechromization fermentation of wet blue dander and application |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS49115098A (en) * | 1973-03-09 | 1974-11-02 | ||
US4100154A (en) * | 1977-04-22 | 1978-07-11 | A. L. Gebhardt Company | Process for recovery and separation of nutritious protein hydrolysate and chromium from chrome leather scrap |
US4401573A (en) * | 1980-05-12 | 1983-08-30 | Luigi Stoppani S.P.A. | Continuous process for the removal of chromium from waste waters and valorization of the recovered chromium |
JPS59179600A (en) * | 1983-03-28 | 1984-10-12 | 和歌山県 | Removal of chromium from chromium-tanned leather chips |
US4483829A (en) * | 1982-02-02 | 1984-11-20 | Giuliano Guardini | Process for recovering proteins and chromium from chrome-tanning waste |
CN1041547A (en) * | 1988-10-17 | 1990-04-25 | 中国科学院生态环境研究中心 | Chrome leather slag comprehensive utilization method and product |
CN102153378A (en) * | 2010-11-24 | 2011-08-17 | 北京化工大学 | Method for preparing amino acid and small molecular peptide composite organic fertilizer and recycling chromium from leather waste |
-
2013
- 2013-03-28 CN CN201310102298.2A patent/CN103143551B/en active Active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS49115098A (en) * | 1973-03-09 | 1974-11-02 | ||
US4100154A (en) * | 1977-04-22 | 1978-07-11 | A. L. Gebhardt Company | Process for recovery and separation of nutritious protein hydrolysate and chromium from chrome leather scrap |
US4401573A (en) * | 1980-05-12 | 1983-08-30 | Luigi Stoppani S.P.A. | Continuous process for the removal of chromium from waste waters and valorization of the recovered chromium |
US4483829A (en) * | 1982-02-02 | 1984-11-20 | Giuliano Guardini | Process for recovering proteins and chromium from chrome-tanning waste |
JPS59179600A (en) * | 1983-03-28 | 1984-10-12 | 和歌山県 | Removal of chromium from chromium-tanned leather chips |
CN1041547A (en) * | 1988-10-17 | 1990-04-25 | 中国科学院生态环境研究中心 | Chrome leather slag comprehensive utilization method and product |
CN102153378A (en) * | 2010-11-24 | 2011-08-17 | 北京化工大学 | Method for preparing amino acid and small molecular peptide composite organic fertilizer and recycling chromium from leather waste |
Non-Patent Citations (1)
Title |
---|
马建中: "《皮革化学品的合成原理与应用技术》", 31 August 2009, article "基本化工材料与酶制剂", pages: 15 * |
Cited By (9)
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CN103525574A (en) * | 2013-10-24 | 2014-01-22 | 山东全杰皮革研究所有限公司 | Method for preparing washing surfactant by utilizing tanning waste chrome shavings |
CN108570105A (en) * | 2018-04-24 | 2018-09-25 | 陕西科技大学 | Acid system takes off method and the application of chromium extraction collagen |
CN108409452A (en) * | 2018-05-18 | 2018-08-17 | 段宝荣 | The preparation method of leaf fertilizer raw material is prepared with process hides chrome leather scrap |
CN112592223A (en) * | 2018-05-18 | 2021-04-02 | 烟台大学 | Preparation method of leaf fertilizer raw material by using tanning chromium-containing leather scraps |
CN112592223B (en) * | 2018-05-18 | 2022-07-22 | 烟台大学 | Preparation method of leaf fertilizer raw material by using tanning chromium-containing leather scraps |
CN112759454A (en) * | 2018-06-01 | 2021-05-07 | 烟台大学 | Preparation method for preparing amino acid liquid surface fertilizer raw material from tanning chromium-containing leather scraps |
CN109052877A (en) * | 2018-08-02 | 2018-12-21 | 广州桑尼环保科技有限公司 | A kind of chromium mud resource reclaim and the method and system of waste residue harmless treatment |
CN109052877B (en) * | 2018-08-02 | 2021-04-13 | 广州桑尼环保科技有限公司 | Method and system for recycling chromium sludge resources and harmlessly treating waste residues |
CN113061062A (en) * | 2021-03-22 | 2021-07-02 | 四川大学 | Method for preparing short peptide-growth-promoting bacterium compound fertilizer by dechromization fermentation of wet blue dander and application |
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