CN100434548C - The method that polym-phenylenediamine is used as adsorbent to recover silver from silver-containing solution - Google Patents

Abstract

The invention discloses a method to reclaim silver from solution with silver, which comprises the following steps: adopting static absorption method; using poly m-phenylenediamine as sorbent; adding poly m-phenylenediamine into silver ion solution with initial concentration at 0.5-102mmol/L; stirring; absorbing 10min-144h; filtering. This invention possesses cheap cost, convenient operation and high adsorption efficiency, which can be used to image fusing waste liquid, plating waste liquid, chemical analysis waste liquid and test waste liquid.

Description

The method that polym-phenylenediamine is used as adsorbent to recover silver from silver-containing solution

technical field

The invention relates to a method for recovering silver from a silver-containing solution using polym-phenylenediamine as a silver ion adsorbent.

Background technique

The traditional methods of recovering silver from silver-containing waste liquid mainly include precipitation method, electrolysis method, reduction substitution method and ion exchange method, but these traditional methods generally have high energy consumption, secondary pollution, and little effect on trace silver. shortcoming. The adsorption method can overcome the shortcomings of the above four methods to a certain extent, so it has great development potential. The adsorption effect of the adsorption method mainly depends on the performance of the adsorbent used. As the most commonly used adsorbent in the adsorption method, activated carbon is mainly used in the recovery of trace or ultra-trace silver in silver-containing waste liquid. Using activated carbon to adsorb and enrich ultra-trace silver in natural water, the adsorption rate is as high as 95.8%, and the minimum detected mass concentration is only 0.025 μg/L (Luo Yongyi, Zhang Kerong, Zhang Yao, etc. Research on the adsorption behavior and mechanism of silver on activated carbon [J]. Environmental Chemistry, 1995, 14(1): 75-79). Use activated carbon for water purification of fruit shells and activated carbon for coal water purification to treat film industrial wastewater containing trace silver (171μg/L), which can reduce the concentration of silver in wastewater to less than 50μg/L National drinking water sanitation Standard, the adsorption capacity can reach 3-5 mg/g (Jiang Ting, Shi Yinyue, Hua Jinyuan. Research on the adsorption of trace silver by activated carbon [J]. Forest Products Chemistry and Industry, 1996, 16(2): 49-53). Although activated carbon can make up for the shortcomings of traditional methods to some extent, it is powerless to high-concentration silver waste liquid due to the limitation of its own adsorption capacity. In addition to activated carbon, activated carbon fibers, chelating resins, poly(1,8-naphthalene diamine) can also be used as silver ion adsorbents due to containing a large number of functional groups, especially poly(1,8-naphthalene diamine) It has the largest silver ion adsorption capacity of 1920mg/g (Li X G, HuangM R, Li S X. Facile synthesis of poly(1,8-diaminonaphthalene) microparticles with a very high silver-ion adsorption by a chemical oxidative polymerization[J]. Acta Materialia, 2004, 52:5363-5374.), but using these three kinds of materials as silver ion adsorbents all have higher usage costs, thus limiting their wide application.

Contents of the invention

The purpose of the present invention is to provide a method for recovering silver from a solution containing silver ions with low cost, convenient operation and high adsorption efficiency.

The method for recovering silver from the silver-containing solution proposed by the present invention adopts a static adsorption method, wherein the silver ion adsorbent adopts polym-phenylenediamine. Polym-phenylenediamine can be synthesized by chemical oxidative polymerization, and it contains NH-, NH ₂ - groups capable of complexing or redoxing with silver ions.

Static adsorption method of the present invention, concrete steps are as follows:

Add poly-m-phenylenediamine to the silver ion-containing solution, stir and absorb for 10 minutes to 144 hours, and then filter; wherein, the initial concentration of the silver-ion-containing solution is 0.5-102mmol/L, and the amount of poly-m-phenylenediamine is the same as that of the silver-containing solution. The proportion of the ion solution is 1-3mg/mL.

The residual silver ion concentration in the filtrate adopts Volhard method titration or measures with plasma absorption spectrometry, then calculates the adsorption capacity of the adsorbent according to (1) formula, and calculates the adsorption rate of silver ions according to (2) formula.

$\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; VM</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; \%</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Q: adsorption capacity of silver ions (mg/g); q: adsorption percentage of silver ions; C _o : initial silver ion concentration (mol/L);

C: concentration of residual silver ions after adsorption (mol/L); V: volume of solution containing silver ions (mL); M: molecular weight of silver (g/mol);

W: weight (g) of polymer added.

According to the change of adsorption capacity with adsorption time when poly-m-phenylenediamine adsorbs a certain concentration of silver ions, the curve of adsorption capacity with time can be drawn, and the adsorption equilibrium time and maximum adsorption at a certain concentration of silver ions can be obtained from this curve. Capacity, and the pseudo-second-order kinetic equation can be used to simulate the adsorption kinetics, so as to obtain the initial adsorption rate constant h.

Because the adsorption performance of adsorbent is affected by adsorption time, initial silver ion concentration, and adsorbent dosage, in the present invention, the initial silver ion concentration range is 0.5～102mmol/L, and the consumption of polym-phenylenediamine is equal to the silver ion-containing solution. The ratio is 1-3 mg/mL, and the adsorption time is 10 minutes to 144 hours. Adsorbents can be doped or dedoped.

In the present invention, the silver ion-containing solution may be a silver nitrate solution, or other silver ion-containing solutions.

Beneficial effects of the present invention: the price of poly-m-phenylenediamine is relatively low, the analytically pure poly-m-phenylenediamine is only 0.3 yuan/g, and the consumption of oxidant ammonium persulfate is considered, and the cost of adsorbing one gram of silver is only 1.56 Yuan, which is far lower than the cost of using poly(1,8 naphthalene diamine) as a silver ion adsorbent, and lower than the price of silver on the market. Moreover, as an industrial raw material, poly-m-phenylenediamine has also been produced on a large scale in China. If industrially pure grade poly-m-phenylenediamine is used as a raw material for preparing silver ion adsorbents, the cost per gram of silver adsorbed is expected to be reduced. To less than 0.3 yuan, the cost is comparable to that of activated carbon as a silver ion adsorbent, and the operation is very convenient, so it has broad application prospects. Silver recovery treatment of ion waste liquid.

Description of drawings

Fig. 1 is the wide-angle X-ray diffraction spectrum after 24 hours of adsorption of doped poly-m-phenylenediamine synthesized under the condition that the oxygen ratio is 1/1 and 102 mmol/L silver ions.

Fig. 2 is the wide-angle X-ray diffraction spectrum after 24 hours of adsorption of de-doped poly-m-phenylenediamine synthesized under the condition that the oxygen ratio is 1/1 and 102 mmol/L silver ions.

Fig. 3 is the XPS spectrum of the doped poly-m-phenylenediamine synthesized under the condition that the oxygen ratio is 0.5/1 after absorbing silver.

Fig. 4 is the XPS spectrum of de-doped poly-m-phenylenediamine synthesized under the condition that the oxygen ratio is 3/1 after absorbing silver.

Detailed ways

Example 1

Take 50 mg of doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 1/1, put it into 25 mL of silver ion solution with an initial concentration of 102 mmol/L at 30 ° C and stir for 24 hours, filter it, and analyze it by Volhard method Residual silver ion content in the filtrate, it can be obtained that the poly-m-phenylenediamine has an adsorption capacity of 386 mg/g for silver ions, and the adsorption rate is 6.8%. The wide-angle X-ray diffraction pattern of the poly-m-phenylenediamine after silver absorption is shown in Figure 1, and it can be seen that the adsorbed silver is mainly in the elemental state. Under the same adsorption operating conditions, the doped poly-m-phenylenediamine synthesized under the conditions of oxygen ratios of 0.5/1, 2/1, and 3/1 was used instead, and the obtained adsorption capacities were 494 mg/g and 275 mg/g, respectively. 235mg/g, the adsorption rates were 8.9%, 5%, 4.3%.

Example 2

Take 50 mg of de-doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 1/1, put it into 25 mL of silver ion solution with an initial concentration of 102 mmol/L at 30 ° C and stir for 24 hours, filter it, and use the Volhard method Analysis of the remaining silver ion content in the filtrate shows that the poly-m-phenylenediamine has an adsorption capacity of 358 mg/g for silver ions, and the adsorption rate is 6%. The wide-angle X-ray diffraction spectrum of the poly-m-phenylenediamine after silver absorption is shown in Fig. 2. It can be seen that the adsorbed silver is mainly in the elemental state. Under the same adsorption operating conditions, the de-doped polym-phenylenediamine synthesized under the conditions of oxygen single ratio of 0.5/1, 2/1, and 3/1 was used instead, and the obtained adsorption capacities were 411mg/g and 306mg/g respectively. , 260mg/g, the adsorption rates were 7.4%, 5.5%, 4.7%.

Example 3

Take 50 mg of doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 0.5/1, put it into 25 mL of silver ion solution with an initial concentration of 42.92 mmol/L at 30°C and stir for 24 hours. Method analysis residual silver ion content in the filtrate, it can be obtained that the poly-m-phenylenediamine has an adsorption capacity of 317 mg/g to silver ions, and the adsorption rate is 13.7%. The XPS of the poly-m-phenylenediamine after silver absorption is shown in Figure 3. It can be seen that the adsorbed silver is mainly in the elemental state and also in the ionic state, and the weight ratio of the two is 76/24. Under the same conditions, changing the adsorption time for 10 minutes, half an hour, 1 hour, 3 hours, 6 hours, 12 hours, 48 hours, 72 hours, and 144 hours, the resulting adsorption capacities were 125 mg/g, 135 mg/g, and 156 mg/g, respectively. g, 189mg/g, 227mg/g, 255mg/g, 394mg/g, 489mg/g, 625mg/g, the adsorption rates are 5.45%, 5.89%, 6.78%, 8.24%, 9.84%, 12.2%, 20.8% respectively , 25.8%, 33%.

Thus, it can be obtained that the equilibrium adsorption time is 144 hours during the adsorption treatment of silver ions with an initial concentration of 42.92mmol//L, and the adsorption kinetics simulation is carried out with the pseudo-second-order kinetic equation. The correlation coefficient of the simulation is 0.9981, and the standard deviation is 4.8688× ^10-4 . . The initial adsorption rate constant h obtained by simulation is 1018 mg/(gh).

Example 4

Take 50mg of doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 1/1, put it into 25mL of silver ion solution with an initial concentration of 42.92mmol/L at 30°C and stir for 24h, after filtering, use the Volhard method Analysis of the residual silver ion content in the filtrate showed that the poly-m-phenylenediamine had an adsorption capacity of 232 mg/g for silver ions, and the adsorption rate was 10%. Under the same conditions, changing the adsorption time to 10 minutes, half an hour, 1 hour, 3 hours, 6 hours, 48 hours, and 72 hours, the resulting adsorption capacities were 120mg/g, 130mg/g, 135mg/g, and 146mg/g , 155mg/g, 250mg/g, 256mg/g, the adsorption rates were 5.22%, 5.66%, 5.88%, 6.35%, 6.75%, 10.6%, 11.2%, respectively.

Example 5

Take 50mg of doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 2/1, put it into 25mL of silver ion solution with an initial concentration of 42.92mmol/L at 30°C and stir for 24h, after filtering, use the Volhard method Analysis of the residual silver ion content in the filtrate showed that the poly-m-phenylenediamine had an adsorption capacity of 165 mg/g for silver ions, and the adsorption rate was 6.9%. Under the same conditions, changing the adsorption time to 10 minutes, half an hour, 1 hour, 3 hours, 6 hours, 48 hours, the obtained adsorption capacities were 125mg/g, 135mg/g, 137mg/g, 140mg/g, 143mg/g g, 170mg/g, and the adsorption rates were 5.3%, 5.66%, 5.74%, 5.87%, 6%, and 7.1%, respectively.

Example 6

Take 50mg of doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 3/1, put it into 25mL of silver ion solution with an initial concentration of 42.92mmol/L at 30°C and stir for 24h, after filtering, use the Volhard method Analysis of the residual silver ion content in the filtrate showed that the poly-m-phenylenediamine had an adsorption capacity of 160 mg/g for silver ions and an adsorption rate of 6.9%. Under the same conditions, changing the adsorption time to 10 minutes, half an hour, 1 hour, 3 hours, 6 hours, 48 hours, the obtained adsorption capacities were 133mg/g, 143mg/g, 148mg/g, 150mg/g, 152mg/g g, 163 mg/g, and the adsorption rates were 5.7%, 6.13%, 6.34%, 6.43%, 6.52%, and 7%, respectively.

Example 7

Take 50 mg of de-doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 0.5/1, put it into 25 mL of silver ion solution with an initial concentration of 42.92 mmol/L at 30 ° C and stir for 24 h, filter it, and use Volhard Method analysis residual silver ion content in the filtrate, it can be obtained that this poly-m-phenylenediamine has an adsorption capacity of 215mg/g to silver ion, and the adsorption rate is 11.4%. Under the same conditions, changing the adsorption time to 10 minutes, half an hour, 1 hour, 3 hours, 6 hours, 48 hours, 72 hours, 144 hours, the obtained adsorption capacities were 133mg/g, 143mg/g, 147mg/g, 182mg/g, 198mg/g, 242mg/g, 283mg/g, 326mg/g, the adsorption rates are 5.77%, 6.2%, 6.4%, 7.9%, 8.6%, 12.8%, 15%, 17.3%, respectively.

Example 8

Take 50 mg of de-doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 1/1, put it into 25 mL of silver ion solution with an initial concentration of 42.92 mmol/L at 30 ° C and stir for 24 h, filter it, and use Volhard Method analysis residual silver ion content in the filtrate, it can be obtained that this poly-m-phenylenediamine has an adsorption capacity of 216 mg/g to silver ion, and the adsorption rate is 9.3%. Under the same conditions, changing the adsorption time to 10 minutes, half an hour, 3 hours, 6 hours, 48 hours, 72 hours, the obtained adsorption capacities were 150mg/g, 161mg/g, 172mg/g, 179mg/g, 228mg/g g, 240mg/g, the adsorption rates were 4.13%, 7%, 7.48%, 7.78%, 10%, and 10.5%, respectively.

Example 9

Take 50mg of de-doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 2/1, put it into 25mL of silver ion solution with an initial concentration of 42.92mmol/L at 30°C and stir for 24h. After filtering, use Volhard Method analysis residual silver ion content in the filtrate, it can be obtained that this poly-m-phenylenediamine has an adsorption capacity of 190mg/g to silver ion, and the adsorption rate is 8.15%. Under the same conditions, changing the adsorption time to 10 minutes, half an hour, 1 hour, 3 hours, 6 hours, 48 hours, the obtained adsorption capacities were 145mg/g, 150mg/g, 157mg/g, 161mg/g, 165mg/g g, 197 mg/g, and the adsorption rates were 6.57%, 6.7%, 6.74%, 6.91%, 7.08%, and 8.46%, respectively.

Example 10

Take 50 mg of de-doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 3/1, put it into 25 mL of silver ion solution with an initial concentration of 42.92 mmol/L at 30 ° C and stir for 24 h, filter it, and use Volhard Method analysis residual silver ion content in the filtrate, it can be obtained that this poly-m-phenylenediamine has an adsorption capacity of 188 mg/g to silver ions, and the adsorption rate is 8.4%. The XPS of the poly-m-phenylenediamine after silver absorption is shown in Figure 4. It can be seen that the adsorbed silver is mainly in the elemental state and also in the ionic state, and the weight ratio of the two is 80/20. Under the same conditions, changing the adsorption time to 10 minutes, half an hour, 1 hour, 3 hours, 6 hours, 12 hours, 48 hours, the obtained adsorption capacity is 150mg/g, 155mg/g, 160mg/g, 165mg/g , 170mg/g, 178mg/g, 192mg/g, the adsorption rates were 6.77%, 7%, 7.3%, 7.4%, 7.6%, 7.8%, 8.8%.

Example 11

Take 50 mg of doped poly-m-phenylenediamine synthesized under the condition of oxygen single ratio 0.5/1, put it into 25 mL of silver ion solution with an initial concentration of 42.92 mmol/L at 30 ° C and stir for 24 h, filter it, and use the Volhard method Analysis of the remaining silver ion content in the filtrate shows that polym-phenylenediamine has an adsorption capacity of 317mg/g for silver ions, and the adsorption rate is 13.7%. Under the same conditions, the initial silver ion concentration is changed to 0.5mmol/L and 2.5mmol respectively /L, 5mmol/L, 10.77mmol/L, 21.55mmol/L, 102mmol/L, the obtained adsorption capacities are 26.9mg/g, 62.4mg/g, 113mg/g, 197mg/g, 250mg/g, 494mg/ g, the adsorption rates are 99.57%, 46.4%, 42.1%, 33.9%, 21.5%, 8.9%, respectively.

Claims (3)

1, a kind of method that reclaims silver from silver-containing solution, it is characterized in that adopting static adsorption method, silver ion adsorbent uses polym-phenylenediamine. 2. The method for recovering silver from a silver-containing solution according to claim 1, characterized in that the specific steps of the static adsorption method are as follows: adding poly-m-phenylenediamine to the silver-containing solution, stirring and adsorbing for 10 minutes- 144 hours, and then filter; wherein, the initial silver ion concentration of the silver ion-containing solution is 0.5-102mmol/L, and the proportion of poly-m-phenylenediamine to the silver-ion-containing solution is 1-3mg/mL. 3. The method for recovering silver from silver-containing solution according to claim 1, characterized in that said poly-m-phenylenediamine is doped or de-doped poly-m-phenylenediamine.

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