Operating Principle

The reactor for acid treatment of quartz sand operates based on a combination   of chemical reaction   and   gravitational settling The working process consists of three key stages:   acid treatment ,  gravitational settling   and   product unloading .

1. Acid Treatment Stage

Chemical reaction between acid and impurities:

• Quartz sand is loaded into the tank and filled with acid (HCl, H₂SO₄, or HF)
• The acid reacts with iron oxides, aluminum, and other metal oxides on the surface and in the cracks of quartz grains
• Main reactions:
  • Fe₂O₃ + 6HCl → 2FeCl₃ + 3H₂O (dissolution of iron oxide)
  • Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O (dissolution of aluminum oxide)

Mixing:

• Mechanical or gas mixing ensures full contact of the acid with quartz sand
• Ensures uniform reaction and high efficiency of impurity removal
• Temperature and reaction time are controlled to achieve optimal purification

2. Gravitational Settling Stage

Separation of solid and liquid phases:

• After the reaction is complete, mixing stops and gravitational separation begins
• Purified quartz sand grains (higher density) settle to the conical bottom
• Spent acid and dissolved impurity salts (lower density) remain in the upper layer

Advantages of the conical design:

• The conical bottom concentrates the settled quartz sand at the lowest point
• Prevents material distribution, simplifying subsequent unloading
• Provides a stable bottom product flow

3. Unloading and Separation Stage

Sequential unloading:

• Draining spent acid Spent acid solution is removed through the top or side drain nozzle
• Quartz sand unloading Purified quartz sand is unloaded through the large diameter bottom flange (DN700/DN400)

Complete unloading:

• The conical discharge opening ensures complete unloading without residue
• The large diameter flange prevents clogging by fine sand and debris
• Periodic or continuous operation is possible