Assessment report (Digested) on The Kemco Witman by A Calcium Carbonate Producer who uses the Kemco Witman (2 units) in Japan “Kemco Witman” Centrifugal Powered Screw Ejecting Dryer 1 Part 2 : Customer report

1) Background: Problem Solution: 2 A)Post primary crushing:In order to produce a quality product, Calcium Carbonate is washed & dried before being transferred to grinding and de-dusting processes. B) Products: Moisture Drying process Application By Kiln Dryer 10mm-3mm 6% down to less than 1% Calcium carbonate 3mm-0mm 15% down to less than 1% Calcium carbonate The moisture content to be fed to grinding and de-dusting processes shall be less than 1%. Problems and solution for drying: The problems by Kiln dryer: Solution by Witman (see page 6 for details) 1) Initial investment is high. 1) Saved by 70% 2) CO 2 emission is high. 2) Saved by more than 50% 3) Energy cost is high. 3) Saved by 62% to 76% (62% for 10-3mm and 76% for –3mm) 4) Silt in the feed can be adhered 4) N/A to the inner wall of Kiln dryer. 5) Large space requirement.5) L 1.5m x W1.4m x H1.1m Kiln dryer: 9m length and 1.5m diameter 6) Operator is required 6) Un-manned operation

2) The performance at the actual production line: 3 A) Feed size 10-3mm 3-0mm B) Moisture 1) Feed Moisture content 6% 15% 2) Products By spin only 0.77% 1.2% By spin and heat 0.5% 0.85% C) Production volume 5 t/h 5 t/h D) Wash effect by “Working water”. E) Size distribution of the feed and products. Silt contained in the feed is removed by There is no change of size distribution between “Working water” as shown in the picture feed and product. However, individual cases are below. subject to test results at the Kemco test plant. Production yield is 93%. Before After Feed Products Fine particle dust water Sieve mesh size Lime stone, 3-0mm, 5t/h

3) - a)The best drying analysis for the Witman heater: 4 Drying efficiency analysis of the Kemco Witman heater is procured by thermal calculation using the temperatures measured at 5 detecting points (Q1 to Q5). Key: Q1 : The calorie to be evaporated. Q2 : The calorie to be used for heating the feed. Q3 : Heat loss from the body of Witman Q4 : Calorie in the exhaust air. Q5 : Calorie in the dust water. WaterMaterial Water Heat

5 Q1 :The calorie to be evaporated Q2: The calorie to be used for heating the feed Q3: Heat loss from the body of Witman Q4: Calorie in the exhaust air Q5: Calorie in the dust water Heat temperature: 110 o C Heated air volume 41m 3 /m 68.5% of all the given calories are used for evaporation. In the case of feed being 3-0mm, the heater shall be used for obtaining the targeted moisture content, say less than 1% (as shown In page 3). The above is the result which was obtained through thermal calculations by using the temperatures from five detecting points (Q1 to Q5) when the products are in the best drying condition. 3) - b)The best drying analysis for the Witman heater:

4) Comparison between Kiln dryer and The Kemco Witman: 6