scholarly journals Process features of neutralization of technical sulfuric acid with natural limestone

2019 ◽  
Vol 58 (4) ◽  
pp. 110-118
Author(s):  
Sergey A. Vzorodov ◽  
◽  
Anton M. Klyushnikov ◽  
Keyword(s):  
Sulfuric Acid ◽  
Sulfur Dioxide ◽  
Ph Value ◽  
Continuous Process ◽  
Pulp Density ◽  
Internal Diffusion ◽  
Sulfur Dioxide Emissions ◽  
Sulfuric Acid Plant ◽  
Concentrated Sulfuric Acid ◽  
Neutralization Time

The work was devoted to the solution of the environmental problem associated with the disposal of sulfur dioxide emissions from metallurgical production at the Nadezhda Metallurgical Plant (Norilsk, Norilsk Nickel PJSC). For utilization of sulfur dioxide it is planned to build a sulfuric acid plant. Concentrated sulfuric acid produced at plant is planned to be neutralized with natural limestone. This work presents the results of the study on the neutralization of concentrated sulfuric acid with limestone pulp from the Mokulay deposit (Norilsk). The influence of the following parameters was investigated: limestone consumption, acid dosing rate, limestone pulp density. It is established that the process is limited by the internal diffusion of acid through the layer of gypsum. In order to eliminate internal diffusion process it is advisable to carry out neutralization in a periodic mode by introducing a strictly measured amount of acid into an excess amount of limestone pulp. This process allows one to speed up the process of neutralization in 3-3.5 times and achieve a higher value of the final pH of the pulp comparing with continuous process. Carrying out the process in the periodic way also makes it possible to achieve the complete absence of the release of acidic off-gas during neutralization. The optimal values of neutralization parameters were determined as the following: limestone pulp density was 11-12%, acid delivery time was 40 minutes, neutralization time was 20 minutes, and final pH value was at least 6.5, while the limestone feeding was an excessive by 22-28% from stoichiometry. It was shown that an increase in the limestone pulp density is impractical because it will lead to an increase in the duration of neutralization, as well as to a sharp increase in the viscosity of the gypsum pulp. That, in its turn, makes gypsum pulp difficult to flow from the neutralization apparatus. It was recommended to filter the resulting pulp in order to obtain a gypsum cake with a moisture content of about 55%. It was recommended to store cake on a special site. A flowsheet has been developed and process schedules have been implemented for the design of a neutralization plant with a capacity of up to 2 million tons technical sulfuric acid per year.

Study on the Treatment of Phosphate-Containing Waste Water by Modified Fly Ash

2012 ◽  
Vol 534 ◽  
pp. 328-332
Author(s):  
Juan Juan Song
Keyword(s):  
Waste Water ◽  
Sulfuric Acid ◽  
Fly Ash ◽  
Ph Value ◽  
Adsorption Efficiency ◽  
Drying Time ◽  
Phosphorus Containing ◽  
Concentrated Sulfuric Acid ◽  
The Impact ◽  
Modified Fly Ash

In this study, fly ash was modified by concentrated sulfuric acid, and it was used in the treatment of phosphorus-containing wastewater, then we have investigated the impact of the different modification conditions on the adsorption, the results show that: in the condition of 5g of fly ash by adding 0.15 mL of concentrated sulfuric acid and 3 mL water, 1.5 h of drying time, the temperature of 100°C, the effect of removaling Phosphorus is the best,and the adsorption efficiency can reach 94.6%. The adsorption rate was fast, and the adsorption can react in condition of wide pH value.

INFLUENCE OF EXTRAGENT PREPARATION METHODS ON CHROMATICITY OF DIFFUSION FACILITY SEMIPRODUCTS IN THE BEET SUGAR MANUFACTURE

2019 ◽  
Author(s):  
В.О. ГОРОДЕЦКИЙ ◽  
С.О. СЕМЕНИХИН ◽  
Н.М. ДАИШЕВА ◽  
И.Н. ЛЮСЫЙ ◽  
Н.И. КОТЛЯРЕВСКАЯ ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sulfur Dioxide ◽  
Sugar Beet ◽  
Ph Value ◽  
Preparation Methods ◽  
Beet Root ◽  
Sulfuric Acid Treatment ◽  
Beet Pulp ◽  
Sugar Beet Root

В лабораторных условиях исследовано влияние трех наиболее распространенных в свеклосахарной промышленности способов подготовки экстрагента обработки его сернистым ангидридом, серной кислотой и серной кислотой с добавлением суспензии гипса на цветность полупродуктов диффузионного отделения диффузионного сока и свекловичного жома. Для проведения исследований корнеплоды сахарной свеклы измельчали в стружку, сортировали с целью получения значения шведского фактора выше 10 единиц, затем готовили образцы поликомпонентного экстрагента со значением рН 5,25,5 и температурой 7072С тремя вышеуказанными способами. Затем проводили диффузионное обессахаривание свекловичной стружки при температуре 7274С в течение 30 мин, после чего промежуточный сок сливали и продолжали дальнейшее обессахаривание в течение 30 мин. Гидромодуль при проведении 1 ч диффузионного обессахаривания составил 1 (единицу). После этого полученные диффузионные соки и обессахаренную стружку отбирали для исследований. Установлено, что обработка экстрагента сернистым ангидридом обеспечила наименьшую цветность диффузионного сока 350 усл. ед., что более чем на 30 ниже, чем цветность диффузионного сока, полученного после обработки экстрагента серной кислотой с добавлением суспензии гипса, и в 6 раз ниже, чем после обработки экстрагента только серной кислотой. Обработка экстрагента сернистым ангидридом обеспечивает жому сохранность цвета свекловичной стружки и при дальнейшем его применении для производства пищевых волокон исключает необходимость осветления различными реагентами, что повышает качество готового продукта и снижает его себестоимость. In the laboratory the influence of the three most common methods of preparation of the extractant in the sugar beet industry treatment with sulfur dioxide, sulfuric acid and sulfuric acid with addition of gypsum suspension on the chromaticity of the chromaticity of intermediate products of diffusion facility diffusion juice and beet pulp was studied. For research, sugar beet root crops were ground into chips, which were sorted to obtain the value of the swedish factor above 10 units. Then the samples of the multicomponent extractant with a pH value of 5,25,5 and a temperature of 7072C by the three above methods were prepared. Further diffusion desugarization of beet chips at a temperature of 7274C for 30 minutes was carried out, after which the intermediate juice was drained and further desugarization for 30 min continued. Hydromodule during 1 h of diffusion was 1 (unit). After that, the obtained diffusion juices and chips were selected for research. It was found that the treatment of the extractant with sulfur dioxide provided the lowest color of the diffusion juice 350 conventional units, which is more than 30 lower than the color of the diffusion juice obtained after the treatment of the extractant with sulfuric acid with the addition of gypsum suspension, and 6 times lower than after the treatment of the extractant only with sulfuric acid. Treatment of the extractant with sulfur dioxide provides the pulp with preservation of the color of beet chips and its further use for the production of dietary fibers eliminates the need for clarification by various reagents, which improves the quality of the finished product and reduces its cost.

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