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Raymond® Impact Mills

Low Cost Grinding of a Wide Variety of Materials

The Raymond® Series 3 Imp™ Mill is a versatile and dependable high-speed airswept swing hammer impact mill designed for fine and medium grinding of soft non-metallic minerals, coals, various chemical compounds, food products and other materials. Almost any solid material with a nominal 1 inch top size that is softer than 2 on the Mohs Scale can be effectively pulverized to a fineness from 1,000 microns to as little as 5 microns.

The Raymond® Imp™ Mill system has the flexibility needed to allow it to both pulverize and dry the material simultaneously


Standard Imp Mill Systems

The Raymond® Series 3 Imp™ Mill system is the ideal solution to many size reduction applications requiring pulverizing of a variety of materials. A typical system consists of the Imp™ Mill with either rotary or vibratory feeder, elevated in-stream classifier, system fan and cyclone. This basic configuration has proven itself the world over.

Raymond® Imp Mill System with Flash Drying

Many materials contain a certain amount of free water in the form of moisture that must be removed in order to increase the value of the pulverized material and to allow it to be handled more efficiently.

The Raymond® Imp™ Mill system with flash drying requires a source of heated air that can be in the form of a fired air heater or waste heat source. The heated air is used to flash dry the material as it is pulverized and swept from the mill. Depending on the initial moisture content of the feed, a portion of the dried product may be combined with the moist feed material in a double paddle mixer. This “conditioned” feed is easier to handle and is more efficiently dried and pulverized. A vent is provided to remove a portion of the moist air and the balance of the warm air is returned to the system where it is mixed with fresh, warm air coming from the air heater.

Raymond® Imp Mill System with Flash Calcining

In addition to free moisture, some materials, such as gypsum, contain chemically bound water, which must be removed in order to change the physical characteristics of the material. This process, known as calcining, can be easily accomplished with a Raymond® Imp™ Mill system.

Essentially similar to flash drying, the Raymond® Imp™ Mill system with flash calcining is provided with a number of special features which make it suitable for the higher temperatures involved. Our experience in the processing of gypsum, by-product gypsum and waste wallboard provides our customers with a single source of equipment supply for processing gypsum and the manufacturing of gypsum wallboard stucco.

 
Airflow and Power Requirements for Raymond® Imp Mill™ Systems

Mill Size
Nominal Airflow - *
Fan Power
Mill Power-min
Mill Power-max
Turbine Power
 
acfm
M3/h
hp
kW
hp
kW
hp
kW
hp
kW
13
1,000
1,700
7.5
5.5
20
15
25
19
5
4
43
3,000
5,100
20
15
30
22
75
55
15
11
53
6,000
10,200
40
30
50
37
150
110
25
18
63
12,000
20,400
75
55
125
93
250
185
50
37
83
25,000
42,500
150
110
300
223
500
375
100
90
103
36,000
61,200
250
185
400
315
900
900
125
90

*Airflow for many applications will exceed nominal values


Nominal Capacity of Raymond
® Imp Mills-stph

Material
Moisture
Fineness
Mill Size
 
Initial - %
Final - %
% Passing
Mesh
13
43
53
63
83
103
Aluminum Tripolyphosphate
20
0.5
75
325
0.6
1.8
3.6
5.9
12
18
Bark
57
45
90
8
0.5
1.4
2.8
4.5
9.0
14
Calcium Carbonate
30
0.5
99
325
0.5
1.5
3.0
5.0
10
15
Clay
40
1
99.9
325
0.3
0.8
1.5
2.5
5.0
7.5
Clay, Ball
25
2
90
200
1.0
2.7
5.4
9.0
18
27
Coal
8
1
99
20
0.3
1.0
2.0
3.0
6.0
9.0
Corn, Cooked
40
12
85
200
0.3
0.7
1.5
3.0
6.0
9.0
Gluten, Vital Wheat
67
10
95
60
-
-
0.2
0.3
0.5
1.0
Gypsum (FGD calcining)
21*
5.5*
75
325
1.3
3.5
6.7
13
28
40
Gypsum (Natural calcining)
21*
5.0*
70
325
1.2
3.1
6.0
12
26
36
Gypsum (Waste)
-
-
90
100
0.8
1.7
3.8
7.5
15
23
Insecticides
-
-
90
325
0.8
2.0
4.0
6.9
14
21
Kaolin Clay
15
1
99.9
325
1.6
4.5
9.0
15
30
45
Lignite
40
22
99.5
20
0.7
2.0
4.0
6.5
13
20
Lime Products
17
1
95
200
1.0
3.0
6.0
10
20
300
Litharge
-
-
99
200
0.4
1.3
2.5
4.2
9.2
12
Peat
50
8.0
95
100
0.2
0.3
0.7
1.4
2.7
4.0
Phosphate Compounds
-
-
75
270
1.3
3.1
7.2
12
24
36
Pigments
-
-
95
325
0.2
0.5
1.0
1.7
3.4
5.1
Soy Flour
-
-
95
100
0.8
2.0
4.0
7.0
14
21
Soy Protein
73
8.0
50
100
0.1
0.2
0.4
0.8
1.5
2.3
Starch
-
-
99
200
1.0
2.0
4.5
9.0
18
27
Stearate Compounds
60
0.1
95
325
0.1
0.2
0.3
0.5
1.0
1.5
Sulfur Compunds
-
-
98
100
0.4
0.8
1.7
3.4
6.8
10
Sunflower Hulls
15
7.0
25
50
0.5
1.5
3.0
5.0
10
15
Talc
15
0.2
99.5
325
0.7
1.8
3.6
6.0
12
18
Tri-Calcium Phosphates
50
0.5
99
325
0.1
0.3
0.6
1.0
2.0
3.0
Wood Waste
55
30
85
10
0.5
1.5
3.0
5.0
10
15

*Total moisture at maximum airflow
 

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