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郑州大学研究生毕业论文

Abstract

The shortage of

material

for paper

making

will last for

years.Non-wood

fiber

especially wheat straw will be

important

component

of materials

for paper

making.

Steam

explosion

pulping

is

new kind

ofmethod

for pulp

making,witll

its

lligh

yield'

good physical properties,low energy

consumption

and low

pollution

discharges.But

the

low level ofbrightness

limit

its usage.Few researchers focus

their

eyesight

on

the

bleaching

of wheat straw pulp.In this

paper,the

bleachablity of exploded pulp

from

wheat straw was

studied.

The

research

showed that exploded pulp could

be

bleached

witll

OQP

bleaching.

Through

the study

of

bleaching

on

wheat sll-aw,it

was

found

that oxygen

delignification

conditions,namely

pulp

consistency 5%,NaOH

charge

14%,MgS04

O.5%,02

pressure

O.8MPa,140℃and

hours,resulted

in

better

effect

of

delignification

and

small

loss offiber.

The

Optimal

process conditions of H202

bleaching are-consistency

10%,HE02

3%,Na2Si03

3%,MgS04

0.5%,the

brightness

reached

30%SBD.

Pressurized/high

temperature

peroxide bleaching ofwheat straw pulp was carried

out,The

optimal

process

conditions

of H202

bleaching

are:consistency

10%,H202

3%,Na2Si03 3%,MgS04 O.5%,the

brightness

reached

30%SBD.The

research

showed that the effect of

transition

metal

ions

on

hydrogen

peroxide

bleaching

of

non-wood

pulps was notable.Pretreatment

to

decrease

the

contents

of Cu2+and

Mn2+

is

unavoidable.The

mechanism

ofaction is

studied.

Key words:wheat

straw,steam

explosion pulp,oxygen delignification,hydrogen

peroxide,OQP