leaching of nacl using water as solvent

8/10/2019 Leaching of NaCl using water as solvent

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Department of Chemical Engineering

University of San Carlos Technological Center

Nasipit, Talamban, Cebu City

ChE 422

Chemical Engineering aboratory !

Leaching

"eaching of NaCl#San$ %i&ture using 'ater as Solvent(

)n initial report submitte$ to

Engr* %ay +* Tampus

by

roup 4

oyao, )lger -r* S*

%anlangit, .irc/ 0ran$on *

Siclot, .arynne 0ernar$ine *

December !1, 2!4


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1. Objectives

Compare single3stage, crosscurrent, an$ countercurrent bea/er3scale e&traction

operations base$ on e&traction efficiency $ata*

Dra the e5uivalent graphical solutions for multiple3stage e&traction operations*

2. Processed Data and Discussion

Table 1. Extraction Efficiency Data

E&traction operation )mount of solvent E&traction efficiency "6(

Single3Stage

!7 m 7*89

8 m ::*997:

: m ;!*!727

%ultistage Crosscurrent

: m

"2 stages of 8 m( 9!*7:!

: m

"8 stages of 2 m(97*819

: m

"4 stages of !7 m(9:*72:1

Stea$y3state %ultistage

Countercurrent: m

raffinat

e98*7299

e&tract 9;*1:92

The most efficient e&traction operation for salt3san$ mi&ture using ater as a solventis the stea$y3state multistage countercurrent e&traction operation ith an e&traction

efficiency of 9;*116* The least efficient operation ith only 7*896 efficiency is the

single stage e&traction ith the smallest amount of solvent use$*


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V

3

V

2

V

1

M

1

M

2

L

1

L

2

=or multistage e&traction operations, having more stages means higher e&traction

efficiency* =rom the table, it is shon that having a single stage for the e&traction process

using :m of solvent only gives ;!*76 efficiency, hereas multiple stages give

efficiencies of more than ninety percent* =or a certain amount of solvent, $ivi$ing it into

several stages ill give a more efficient e&traction because it creates more e5uilibrium

stages*

Comparing crosscurrent an$ countercurrent e&traction operations, countercurrent

leaching is more efficient* oever, in countercurrent leaching, the $riving force in

every stage remains the same*

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L

2

L

1

L

3

V

4

V

3

V

2

V

1

M

1

M2

M

3

Figure 1. ra!hical solution of t"o#stage crosscurrent leaching using $%% &L "ater as

solvent.

Figure 2. ra!hical solution of three#stage crosscurrent leaching using $%% &L "ater.

4


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M

1

L

1

V

1

V

2

M

2

L

2

V

3

M

3

L

3

L

4

V

4

V

5

M

4

Figure '. ra!hical solution of four#stage crosscurrent leaching using $%% &L "ater.

5


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Figure (. ra!hical solution of steady#state &ultistage countercurrent leaching.

=igures !34 sho the e5uivalent graphical solutions for the multistage e&traction

operations* There are cases in leaching in hich the e5uilibrium line in the &y $iagram

$eviates from the y?& line because of insufficient contact time, a$sorption of the solute

on the soli$, or the solute being soluble in the soli$ "ean/oplis, 28(* The e5uilibrium

lines in =igures !, 2 an$ 8 fall belo the 47@ line* >oever, instea$ of the possible causes

state$ above, this may be because a small amount of san$ that ha$ not yet settle$ from

mi&ing as inclu$e$ in the measurement of the $ensity*

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'. )!!endices

Table 2. Data for density#concentration !lot for *a+l solution

$ensity "g#m( mass fraction of NaCl

*99:2 *

!*272 *4!

!*724 *;

!*;72 *!21

!*!!21 *!:1

!*!44 *2;

!*!;41 *27!;

0.00 0.05 0.10 0.15 0.20 0.25 0.300.90

0.95

1.00

1.05

1.10

1.15

1.20

f(x) = 0.75x + 0.99

R = 1

mass fraction of NaCl in water

density, (g/mL)

Figure ,. Density versus &ass fraction of *a+l in "ater

Table '. Fresh feed -beaer /00 data

$ensitometer rea$ing "g( 3!!*!;temperature "@C( 21*

$ensity "g#m( !*!!;

mass fraction of NaCl in ater *!::2

mass of NaCl in fresh fee$ "g( 29*1999

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Table (. Data for single#stage extraction o!eration

bea/er

amount ofater "m(

$ensity of NaClsolution "g#m(

mass fraction

of NaCl inoverflo

mass of NaCle&tracte$ "g(

e&tractionefficiency "6(

< !7 !*:2! *9!8 !7*!:2 ,%.'%%


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%ass of NaCl from mass fraction $ata

mass of NaCl=mass fractionof NaClwater mass of water

1mass fraction of NaClwater

mass of NaCl=0.1662149.48g

10.1662

mass of NaCl=29.80 g( feed)

E&traction efficiency

=mass of salt extracted

mass of saltfeed 100

=15.02 g29.80 g

100

=50.39

Table $. Data for gra!hical solution of &ultistage crosscurrent extraction o!eration

mass fraction of NaCl

in overflo, &

mass fraction of NaCl

in the li5ui$ fee$, y

mass of soli$#mass of

li5ui$ in fee$, N

bea/er


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leaching of nacl using water as solvent

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