Heat Exchanger World magazine April 2024 | Page 37

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Materials

Agitators T = 230 ° C

98 % Sulphuric acid

T = 260 ° C

Autoclave

Flash vapor stage nr . 1 , T = 212 ° C

Steam T = 260 ° C

Flash stage nr . 1 T = 212 ° C

Preheater nr . 1 T = 160 ° C

Figure 2 . HPAL for laterite nickel with indirect heat transfer ( self-cleaning heat exchangers ).

Figure 3 shows that it would also be possible to modify the existing directly heated laterite nickel processing plants into an indirectly heated configuration employing self-cleaning heat exchangers . Installing the indirectly heated flow path employing self-cleaning heat exchangers parallel to the existing directly heated flow path creates a unique flexibility in the operation of the plant enabling an easy return or fall-back from the ‘ new ’ technology on the ‘ old ’ technology , if necessary .

Because of the reliability of the self-cleaning heat exchangers , the fall-back possibility from ‘ new ’ on ‘ old ’ technology and the large benefits which can be achieved by the operation of the indirectly heated self-cleaning exchangers , the installation of full-size self-cleaning heat exchangers parallel to the existing directly heated installation should be considered , instead of rather costly small-scale pilot-plant testing prior to the installation of full-size self-cleaning heat exchangers .

Figure 3 . HPAL for laterite nickel employing direct heat transfer revamped into indirect heated configuration .

www . heat-exchanger-world . com Heat Exchanger World April 2024

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