Magnesium hydroxide depends on the properties and purity of many uses in various fields, among which its applications can be mentioned:
1) Fire retardant – In fact, it is a type of refractory that is used in various composites due to the high temperature of its decomposition or decomposition of magnesium hydroxide.
۲) از منیزیم هیدروکسید به عنوان خنثی کننده پساب ها و فاضلاب های اسیدی در صنعت کاغذ سازی استفاده میشود.
3) Magnesium hydroxide is used as an additive in plant and chemical fertilizers.
۴) از منیزیم هیدروکسید به عنوان پیش ماده اساسی جهت تهیه ماده با ارزش منیزیم اکسید استفاده میشود که این منیزیم اکسید در خلوص بالا می تواند به عنوان ماده اصلی دیرگدازها در صنعت آجرهای نسوز و پوشش دیواره های کوره ها استفاده می شود. It should be noted that high purity magnesium oxide tolerates temperatures of 2800 ° C well.
5) Magnesium hydroxide is also used as a catalyst in the preparation of some chemicals.
6) Magnesium hydroxide is used as an additive in chemical dyes.
Synthesis methods
Preparation and synthesis methods are:
1) Hydration of magnesium oxide –
In this method, magnesium oxide reacts with water and magnesium hydroxide is produced. This reaction is exothermic and releases considerable heat.
2) Combination of magnesium salt solutions with strong alkaline solutions of magnesium hydroxide
for example: Magnesium chloride is dissolved in solution with sodium hydroxide and magnesium hydroxide is prepared as a precipitate.
Alkaline solutions used in this method: کلسیم هیدروکسید، سدیم هیدروکسید و آمونیوم هیدروکسید میباشد.
3) Electrolysis of magnesium salt solutions
4) Using brine and sea water to extract magnesium hydroxide
Disadvantages
One of the biggest disadvantages of this compound is its poor filtering. Due to the hydrophilic nature of magnesium hydroxide, water does not separate easily and it is very difficult to prepare sediment.
But to solve this problem, a lot of work has been done that improves the physical properties and morphology of magnesium hydroxide.
The most important things that have been done are:
1) Organic or organic additives – in such a way that organic additives are added to the desired solution which contains magnesium chloride salts and alkaline solution to improve its morphology.
2) Use of catalysts Hydrothermalization and high pressure – Although high purity magnesium hydroxide can be achieved, but this is not economical for most factories and will not meet the high demand of this product.
Use of surface modifiers or modifiers – to correct the level of magnesium hydroxide by them. One of the most important cationic modifiers and surfactants is trimethyl ammonium bromide (CTAB), which increases the impurities in the preparation of magnesium hydroxide.
Finally, the production properties can be examined by spectroscopic analysis and devices such as XRD, SEM, BET.
مترجم: مهندس امین مزرعتی
Quoted from reference number: DOi 10.1007/s11705-011-1125-9